I don't know much about your family situation but it sounds terrible. To quote "Do not let what you cannot do interfere with what you can do". In other words, you can't change who your family is or how they have chosen to interact with you, but you CAN choose to unhinge from them and surround yourself with better supportive people.

When you interact with friends, are you listening to them and their needs too or do you jump in with your problems? I find it helpful and therapeutic to listen and help other people. By focusing on their problems and helping them out, It tends to take my mind off of my problems for a while.

Have you tried talk therapy or medication or both? I read your other post about getting depressed when you see other pretty girls etc. This makes me wonder if you need Cognitive Behavior Therapy as well... to help make you cognizant of what you think. Our thoughts play a huge role in our mood. Check out Mind over Mood.