Well, you're young so a lot is still in front of you.. Music is 'happening' on the internet and 'live' these days.. There's a lot of DIY etc. If you choose college wisely it could help with your music career too.. and give you a 'second option' or a few - some people get bored of music or such too, or burnt out or disillusioned.. some prefer playing music 'for the soul' than for money.. and are happy with 'real jobs' (to finance music gear
) and just love hanging out with the band and playing on the wekend..
If you wanna do music 'pro' then some degree of networking is important (so you can create with other good musicians/singers/songwriters..) If you don't want to do music biz and marketing, or some other aspects like graphic design etc, then you better have other people who you can trust who are gonna do it.. (and even then it's good to know enough so that you know what they're doing and if they're going about it right..)
(even some big names got scammed by their managers etc)
It's great that you don't want to 'lose yourself' in social life (cause I've seen some people 'disappear' in 'the lifestyle' of partying etc.) Maybe some small amount of socializing with the right kind of people can bring good results though.. (It depends on the people and what you do.. Obviously, stay away from too much alcohol or iffy things such as drugs etc.)
Sometimes socializing can connect people and make a 'better band' or bring you in touch with other good musicians etc.
If you don't like your weight maybe you can work on it too.. It's important to be FIT and HEALTHY on stage!!
Sorry to hear you got picked on, you sound like a big guy now who can probably scare other people away who'd even attempt any picking, no?
And of course you CAN bring your music to the world!! Why not?
There's tons of bands/artists on CDbaby or iTunes via TuneCore etc.
Can you expect to earn a significant full-time income 'right away'? - probably not, if you work on it (marketing, live gigs, etc) it can happen.. It's mostly not 'overnight', some people do manage to earn quite some money too.. or at least hang out with interesting people and make great music..
Look up Kristin Hersh and CASH music.. Some other artists/musicians seem to do quite well too..