Hello all.

I'll try to keep this short, as I tend to rant and lose track of my original thoughts. So my girlfriend and I have been together 2 1/2 years - our third year anniversary would have been mid-October. We've been through hell together and always stuck it through. Thought I was over her, but she keeps visiting me in my very intense dreams.
She has ASD (mild autism/Aspergers.) Wasn't sure whether to post this here or in ASD forum. I think here would be more suitable. Anywhom, I accept full responsibility for the breakup being 100% "my fault." I've realized my mistake but can't let her go. I've messaged her / called her every few weeks but I've gotten no response. She called me once and we had an 8-minute conversation where I said I still loved her and wanted to get back together. She called the next day and said no.
I'm a persistent bastard who never gives up at anything - one of the factors she found so attractive about me. I've talked with a couple of my female friends who all agreed that she was being unreasonable by not even hearing me out.
This is too damn long already. Point is, I've read a couple posts that said my last resort to get her back was unreasonable and childish but I can't think of any better way of proving how deep my love and regret really is by dropping a few grand on a ring and proposing. Is this a terrible idea? Can I get some thoughts from some aspie/asd folk to better understand her perspective? Really lost here.

I'd appreciate it greatly.