1. You're not a loser. Drop that crap. You're 16; you're learning who you are.
2. You can absolutely get in shape. Plenty of resources around, from Crossfit to gym memberships to simply doing "push aways" at the dinner table and walking more.
3. Unfortunately, you cannot learn wing chun without a teacher.* If you can't find a school in the area, look at what is available. Find something else that interests you. Look at what it is about wing chun that fascinates you and see if that's available in something around you.
*There are a tiny percentage of people who could learn a martial art from books, videos, and other methods other than direct instruction. Your post strongly suggests to me that you don't have that particular combination of natural abilities and talents. Not a dig at you; notice I said a TINY percentage of people.