I can't seem to ever say, do,the right thing!

I have been married for 6 years. The first year was great, the second year even better.I was on top of my career, had a wonderful circle of friends.enjoyed community service, and payed off my home! This is my second marriage, and took me a longtime to find someone whom was established in life(as I was convinced)and at 35yrs old, I was ready to travel, and be carefree, especially after surviving a deadly sarcoma ,that gave me a death sentence!! I had worked very hard in the real estate industry, and several other business adventures to almost retire. However, when the economy down turned, so did my assets.That's when I discovered my husband had none. And, in his last marriage owed $60,000 back child support. I ended up bailing him out on some financial issues he had ,while he promised to "make it up" . That never happened, and he eventually said, that was" never the agreement".To fast forward to now....I put my home up for rent, and after months of my husband's convincing,we both came back to school full time. We made a plan to complete school, get good jobs, and start again..." A new adventure", he promised..I became poor, and lost all my past social life and family connections...My husband got kicked out of school his first year due to a serious battery charge, which devastated me...We also got thrown out of our campus apt.I figured out how to remain in school, and established a new living situation, while my husband fought the legal system,I continued to back him all the way.( He has a trial coming up Dec 2012, which he has not given me any details about). On top of that,soon after,( unannounced to me), his 14 yr old son, moved in with us. I was told to "deal with it". This was where it really got bad. Since then, I have been yelled at, called a "*****", called "selfish", constantly told I am "disrespectful" to him and his son.I have nowhere to study, and expected to always be at home. Everything I say or do, is against them.My husband has called me "stupid" thrown, and destroyed my phone, computer, valuables,cut me off financially, and says I am the "source of his anger". He has turned off my phone, internet service, took my car keys, which caused me to miss allot of school.He constantly tells me he is "genius", "admired", highly "respected", and I do not acknowledge any of this! He tells me I am the intelligence of a 3 yr old, and must treat me as such!
He has been the one working, and I have been struggling through premed.Depending on what food he gives me permission to have ,and selling all my valuables to pay my debts, I have become very lost and confused! I have made it to my senior year, soon to graduate, and three months ago secured a government dream job.I am trying to build myself back up financially and emotionally. But, as I become confident again, I am told by my husband , I am "rebellious" and "disrespectful". The situation got worse, and I moved out, and lived in my car.He convinced me to come back, and the insults are worse. His son joins in agreeing with him. He convinced me that I needed help, and I almost lost my job, and school. I managed to get my head together enough to coast for now. I am normally a very confident, and independent person. Not anymore..I struggle with what I know I need to do, and with what I did so wrong? Please help me, if you can..