I can relate to this in a way...I was homeschooled too and although I never directly confronted my mom to tell her I was having problems, it was very obvious. Her attitude about it was similar, she just seemed to think I was being lazy or stubborn and just didn't want to do my work. I made it through high school, to be completely honest by half the time sneaking a look at the answer books and writing most of the answers correct.
It wasn't until the first semester of paramedic school (almost exactly a year ago) that I finally told her about it and she luckily took it seriously...I guess because she realized I was doing something I really wanted to do and still having problems. I've been on Adderall since then and it's made a huge difference.

As far as meds, I do understand her concerns a little bit...a lot of adhd meds, like Adderall for example, are pretty strong drugs that have a tendency to be abused. I'm not saying you would do that, though. But, there are some meds out there that are for ADD/ADHD that aren't stimulants. I can't think of the names at the moment, but maybe look into that? She may be more willing to let you try those.
Good luck