Hey, man, welcome

I just wanted to offer a couple of little pieces of advice that I found really effective.
First of all, the physique thing. For your slouch there's two things you can start doing. One is the Alexander Technique that Style suggests. The other is pull-ups.
Pull-ups are like the best compound exercise you could do, works your back muscles, arm muscles, abs, etc. Plus, as a bonus, they help to straighten out your spine. Wonderful, no?
Get a pull-up bar and put it up in your kitchen doorway. Then, everytime you go in or out of your kitchen, make yourself do 5 pull-ups. Eventually it'll become habit and you won't even have to think about it.
Good luck implementing your plans, dude. And good luck for the future.