THIS!! Start with something simple like Python. I don't think you need to be good at math to be a good programmer. If you understand the concepts of math theny you will be fine. I heard Rita Wilson say the other day something like "If you keep practising something you can only get better at it". (not a direct quote) Find a Problem then solve it. That is the best way to learn.
Use the OS you are most comfortable with. When it comes to programmming try and learn 1 "thing" at a time. If you trying to learn Python and how to use Linux as well as Python then you learning 2 (or more..) things at once so stick with what you know for now. If you are comfortable with Linux (or Mint as you say) then stay with that because I have found running Python on Windows is a Pain but that could just be the environment we are using. Good Luck and Have fun!
Consistency is very important espcially later on. When the user or client is talking about X and it's called Z in the Database and Y in the code this will cause so much confusion. I think the fact you care means you are good programmer. Don't loose that.
Bummer it would take 51 reasons why I would switch to something as messy as PHP. I was so close to switching.