Why not start college now? Don't know where you live, but most states have accelerated programs where you can earn your AA while still in high school. Even better, spend a few hours in the forums at degreeinfo.com learning how to get a degree quickly and relatively inexpensively. You write well (except for the "eye trouble") and appear to be intelligent enough to test through much of a degree. That will satisfy your father and show him that you are more than just dreaming. Know that, in most cases, parents' wisdom FAR exceeds a child's knowledge. From there (or during the time you're earning your degree), get a job. Any job. I can't imagine you have many bills to pay. Stop spending.
I'd be surprised to see anyone take on a face-to-face mentorship with someone under 18, just because of insurance and legal implications.
Listen to your parents, get a degree (something that can't be taken from you), get a job, build some cash. THEN think about investing.