First of all, you say that you just want to be loved for once in your life, but, you also say that your girlfriend is your only reason for living which sounds to me that you already have love in your life and also that you have already found your reason for not ending things. This is a good thing because it means that you haven't gotten to a place where you feel like you have nothing, unfortunatly, this also comes with a flip side because you are putting all of your hopes and dreams and in truth your entire life into this relationship, allowing your relationship with this girl, another person to be your sole reason for living. Although it is wonderful that you have found someone that makes you feel like your life is worth living, you cannot base your life solely on this girl or this one relationship because then you are not allowing for anything else to happen in your life. You should never allow yourself to become solely dependant on one person, this is putting too much responsibility on the other person and the relationship between the two of you. You need to find something that makes you happy outside of the relationship, this way you know that even without this person you are your own person, that you are you and she is who she is and together you are better and apart you are still yourselves.
Also, I am going to say that alot of your issues stem from the issue of an absent father. Despite what many people like to think in todays' society of broken homes and divorce, a child always longs for a fathers attention and support. Children need a father figure in their lives. Children, despite their age look at each of their parents for certain things. To a child a father is supposed to be the hero, the one who hands out the discipline and the rule maker. A mother is supposed to be the soft place to land, the one who supports and loves her child through anything he/she may be going through. A mother to a child is supposed to be the one person that a child can count on no matter what. And when parents fail to fullfill these images that children have of them then the child sometimes becomes lost, wondering why they have parents like they do, often blaming themselves for an absent parent or a parent who couldn't seem to care less. I will tell you that I myself have a bi polar mother and I know personally how hard it is to deal with this. Bi polar disorder is difficult to deal with regardless of who has it, but, when it is a parent, especially a mother then it becomes even more upsetting and difficult because the mother that you as the child had set aside in your mind as the loving, caring, always supportive, always loving woman is most often not who she is in reality. I am older now and a mother myself and still I have difficulties dealing with my mothers' bi polar, sometimes not answering the phone when she calls because you are never really sure what you are going to get when you pick up, she can be the most loving caring woman in the world one second and then the next she is so hurtful and mean that she can cut you down to make you feel like the worst person in the world and her attitude and temper can change in a flash so again you are never really sure what or who you are getting when you answer the phone or walk through the door. As for the absent father, I too have dealt with this. I grew up with a father who only bothered with me when it was convienent for him and even then he let me do whatever I wanted to just so that he didn't have to be bothered with me and so that I wasn't around too often. This was great as a teen because what teenager doesn't love having freedom and a parent who lets them do whatever they want and they never get in trouble or have to answer for anything they do? But, as I grew older and became a parent myself and started looking back I began to realize that what I thought was my father being the "cool parent" was infact just him not wanting to bother to be a parent. I understand your situation here because I have been through this myself growing up and yes, it is an extremely hard thing for a child to deal with, however, I am living proof that these things do not have to hold you down or dictate how or what you turn out to be. I am a high school teacher, I also help kids who have been abandoned or abused by thier parents. I volunteer for support groups to help people with life altering problems. I have 3 beautiful children who love me more then anything and I am a happy, functioning memeber of society. I have great friends who would do anything for me and I for them. I was like you when I was your age too, I thought that somehow I was responsible for my parents' behaviors and that maybe if I acted different they would be better parents, but, I grew up to realize and understand that I was their child, they were supposed to protect me, not the other way around. I know now that I was in no way shape or form responsible for the way that they chose to parent me or for their actions. I also know now that it is possible to rise above the drama and hurt that comes from this situation and become someone who you are happy to be, someone you are proud to be. So, take it from me, what you are going through right now is hard no doubt, but, it does get better over time and you don't have to let it define you or your life. You get to chose how your life goes, noone else. There is no such thing as a bad life, just bad situations, but, you have the power to rise above it and be happy.
As for rumors and getting bullied. Rumors are nothing more then things created by people who are bored or unhappy with their own lives and therefore they feel the need to involve themselves where they don't have any right to be involved. They figure since they are unhappy that everyone else should be too. Rumors will follow you through life, no matter your age, there will always be people who have nothing better to do then to try to cause trouble for you and bring you down to their level. It is up to you to say "Go ahead, say what you want because I know who I am and I am happy with that and I am happy with my life and I am not going to let you drag me down with you.". The next time that you hear a rumor concerning you or your girlfriend just laugh it off and say "Oh well whatever."...most often when people who are causing the trouble see that it is no longer affecting you or that what they are doing isn't bothering you they will quit because it is no longer entertaining to them. You are a better person then they are and you need to hang onto that. Let them talk, after all, you know the truth and that's all that matters. As long as you are happy with who you are and with your life then what anyone else thinks or says is just static. Concentrate on the positive things in your life and in time I promise you will find that things will ease up and start getting better. You cannot change how others are, not even your parents, but, you can make the choice to be a better person and to be happy. Someone who comes from a situation like yours and mine and finds a way to rise above it and be happy always becomes stronger and appreciates what they have because they had to fight to get to be happy and to be where they are and trust me when you reach this point, it makes everything that you had to suffer through seem so small compared to the happiness you have built for yourself.