Dear FreezeFlame...
In psychology, sexual orientation is not officially determined until the subject has reached the age of 26. This is because many people experiment or are curious, etc. in their younger years. Sometimes their "testing the waters" is because of a bad or difficult prior experience with the opposite sex. Human sexuality is one of the most complex areas of our lives... and not simply understood. Of course, society/culture and religion tend to put their own perceptual filter on issues of sexuality which cause things to become even more confusing for those who are "out of the mainstream" in their sexual focus. Additionally, some report having known that they were "different" since early childhood... many since the age of 5 or so. For them, at least, there is no question about their orientation.
You have not mentioned if you live in a large city. If you do, can you call the local gay hotline or gay teen hotline? It's always free and totally confidential. Being able to talk to a live person who is compassionate and informed could help you move forward with your home situation. If you live in a more remote area, I believe there are gay teen "hotlines" on the internet that you could access as well.
You've also not indicated if you were raised in (or if your mother is involved with) a religious group that is not supportive of gays. These are important issues that could help to determine which approach would be best for you to consider.
Anyone's teen years are, at best; confusing, frustrating, infuriating, intimidating and scary. Adding "being different" in a culture that demands conformity just increases those experiences to a level that is, at times, intolerable. This is one of the reasons for a high rate of suicide among gay teens. Just remember that suicide is a permanent solution to a temporary problem. There are always choices and alternatives, even if you can't think of one at the moment. Give things some time and solutions will reveal themselves to you.
You are fortunate to have friends and some family who do or will accept you as you are. I know you want to just "get this over with" when dealing with your mom, Especially during our teen years, we want everything "yesterday!" But I urge you to consider going slow here. Talk to your friends at school. Call a hot line where they can ask you detailed questions to help give you a better answer. I know you don't want to hear this... but have patience. It's possible or even probable that your mother knows or has concerns about your sexuality... and that her comments about "faggots" are meant to keep you from confirming her suspicions. If this is true for her, perhaps she doesn't want to know for sure because then she would have to deal with it.
The last thing I will share with you here is that she sounds like a very unhappy person. People who are a "bitch" are usually very angry. Also, unless she's only a "bitch" to you, then her anger and "bitchiness" is not about you. Then she's just generally angry and unhappy. People who cause trouble are usually in trouble.
There are many young men and women in this world who are in your shoes right now. You're not alone. There are answers and caring people out there. Stay committed to find the correct answer for you before taking any action. Since your living arrangement options are so limited at this point in your life, take your time and be sure before taking the big step with your mom. Once it's done, you can't turn back... so be as sure as you can be before acting.
I'm sorry for your pain and suffering... but please know that your pain will pass in time. You'll get through this and life will go on and you will experience happier times.