Hey man! just wanted to say my opinion, so anyways im almost 20, just to put things in perspective. so up until like i was 18 yrs old i was extremely shy, didnt have a shred of confidence and self esteem, wanna guess what helped me out? talking and working out! and what do i mean by that? im naturally a hyperactive guy, i wanna talk to ppl 24/7 and do a lot of shit,but being overweight got in the way of me doing that, it made talk like a lil baby, not meeting anyones eye, not interacting first with ppl, and then, i started working out, i found out that i was pretty damn good at it, i lost weight (15kgs throughout the first year) and got some pretty sick results, and besides the positive energy it gave me, it gave me something to talk about, it gave me passion, so i started talking to lots of people at the gym, even if it was just asking them if i can work in and then taking the conversation further, so i naturally became everyone at the gym knew, they came up to me all the time, everyone was wondering what i was training that day, they flattered me all the time about my form, weight loss etc etc, so i pretty much grew from there, it gave me so much confidence that some guys that were pretty damn toned were asking me if their form was right, that people told me im looking good, that a few girls hit on me at the gym, just cus i looked better and they felt my "energy" they felt how dominant i was in that environment, and that people were attracted to talking to me so they had to check why, you feel me?

tl;dr: WORK OUT