Pick something elementary to prove (by which I mean requires little prior knowledge) - like the fact that the square root of 2 cannot be expressed as a fraction and look up the proof. Spend time understanding not only the proof itself, but also, crucially, why it is important to prove things in this kind of formal way. Here lies the beauty of mathematics at first. Later you will find exciting results, at first, there are only beautiful proofs.
You are then probably going to have to go back and do some rote-work. I think you probably need to crunch some calculations to get comfortable enough to ever get really good.
The good news is that with the excitement in hand, you should be able to carry on through the rote stuff and then start on some undergrad courses (plenty are published for free online) that have no prerequisites. Logic and number theory are good for lack of existing knowledge - both come from sets of axioms.
You are then probably going to have to go back and do some rote-work. I think you probably need to crunch some calculations to get comfortable enough to ever get really good.
The good news is that with the excitement in hand, you should be able to carry on through the rote stuff and then start on some undergrad courses (plenty are published for free online) that have no prerequisites. Logic and number theory are good for lack of existing knowledge - both come from sets of axioms.
[Obligatory, 2. ???, 3. Profit]