I'm going to tell you something that was told to me, by someone who is quite intelligent on matters like this...
Stop caring about impressing others because no one gives a shit whether you succeed or fail.
See, it's not that no one cares about you. That is not true. Personally, I would love to see you succeed in something you love, whether it's music or art or whatever..
It's that they are more worried about their own shit to notice what you are doing.
So the only one you should succeed for is YOU.
Lose weight for you. Get a better job or go to school for YOU. Worry about what YOU think about YOU.
Once you are satisfied with yourself, your confidence will go up.
Stop caring about what others percieve you as and fucking live your life man.
plus:
you are amazing.
nobody thinks that about you - and if they do, they arnt worth your time.. becuase they are prolly in way worse condition than you are. because your not in bad condition.
you have goals.
you know what you want.
you know what you have to do to get there.
thats more than alot of people i know.. me included.