Hello Keith, there is a big difference between your parents wanting you to continue uni, compared to how you are feeling and what you want.
I was forced into doing a course straight after year 12, that's not what I wanted, I wanted to work, and the 3 year diploma was a waste of time, I didn't any bit of it and a waste of time.
If your parents are kicking you out because you're stopping uni isn't fair, so can I suggest you say that you are postponing your studies for the time being and can return to do them later on, other than that, there are ways to get you into your own place in the situation you 're in.
Maybe you should have been helped to get your car licence, and encouraged to find a small part time job.
Your local 'community health centre' does provide an exercise program at least once a week, somewhere for you to begin, but please let me know how you can move into a unit for yourself.