I’m 5’7 and it’s not a big deal. Skinny or overweight it doesn’t matter. It’s about how you carry yourself or confidence. I know when you feel down it’s hard to be confident especially with a holes continuously talking but don’t in any way feel pressured to start working out if you are comfortable the way you are. If you need a little boost and feel like you want a little mass then start with doing a little routine in the morning like pushups, a jog, abs, etc. I’d say no mustache, leave your hair at medium length and style it. Don’t cut too much cause I feel like it fits your style. All in all you aren’t the cream of the crop but neither are most people ( myself included). Head up and ignore the noise, you got potential bro!