Meh.
Ive already gone through the whole trying to 'kill myself because I am useless' phase.
Fortunately for me I have a brain and my years at university saved me. I dont take any shit from anyone now, and wouldnt ever let anyone treat me how you are letting them.
You need to take controll of your own self and stop doing things just for the pleasure of others.
Believe me, I feel very lucky now to never have tried having a BF before as I would have just had to deal with more emotional problems from both him and my family.
Being single and in controll of your life is being happy, and if you do let anyone else into your life it should be because they add extra happiness.
I dont actually need profesional help, I can help myself. But you sound stuck and far more further into the 'I was abused and then messed up my own life' scenario then I ever were.
But I think about killing my family everyday, but have been doing so for a very long time and nothing happens, and I have managed to gain a bit of command over them now.
Humans are animals, most of them are wild, instinctive and ignorant, very few are tame, cuddly and nice.
The opposite is the case for dogs, buy a snorgly puppy and save your happiness.