Many times it boils down to one thing - we have to care enough about OURSELVES in order to get where we want to go! Some people have been abandoned by their families for whatever reason. They, like you, don't have anyone to fall back on. But they don't let that stop them. If they want their dreams bad enough they go ahead and GET them! But they LOVE themselves. They care enough about themselves to go ahead and fight for what they want. And YOU can do that too, if you care enough about yourself.
Don't let anyone else get in your way. Don't let your family determine whether or not you find and GET your dreams. Why should they stop you? If they didn't care enough to support you, then go ahead and do it yourself! You can do this! Talk with your therapist about this. Talk with him about your self-esteem. Evidently that has been suffering. Get it built back up, and I'm SURE you'll be able to do whatever you want to do! You only have one life, and to allow your dreams to slip by would be a tragedy.
God bless you -- I know you can do whatever you set your mind to. Take care and keep us posted. Hugs, Lee