This sounds good to me. My point is just that you should be aware of the potential workload of attending a top ranked university and be ready for it.
Back when I was a student there is something that I eventually figured out: If you study very hard, start your homework early, and make a strong effort to always keep ahead in your studies, then it is much less stressful to be a student at an academically demanding university. One person I know has said “you have to want to do it”. If you want to do it then you should be fine.
Which gets back to your first question: What are your chances? This is very hard to predict. Your GPA is very good for someone who needed to take two months off in the middle of high school. To me your situation looks like one where it is hard to predict your chances at a top 20 university. I think that you should just apply to universities and colleges that will be a good fit for you, and see what happens.