f you are concerned about other people's negative thoughts about you, it is a sign that you value their opinions over yours. Once you are confident, what other people think doesn't matter. I've gone through depression and insecurities about my skin, hair, body-type, clothes, living arrangements, and school I attend. Only until I conquered each one was I able to be confident with myself. People can still say hurtful things to me and it may hurt my feelings, but only for a little bit instead of a stinging, lingering thought.
If you are truly willing to get in better shape, here is my advice:
+ Diet is extremely more important than exercise, but getting in shape requires adhering to both.
+ Going to the gym is not for everybody. You can easily hire a personal trainer or torrent a home workout DVD set (P90x is best for strength training, Insanity is best for cardio). Also, a huge misconception is that you need fancy exercises or equipment to get in shape. Simply investing in a jump rope and jumping until you are done is all that is required.
+ Eat 5 smaller meals a day instead of 3 big meals. This makes your metabolism work harder and burn faster, and the result is that after a week or two of doing this, you will get full faste
+ Drink a glass of water with every meal
Also realize that YouTube is a breeding ground for trolls and the assholes of the Internet. What they're able to type and able to say in real life are two different things.
I hope this helped.