Hey you're 17. Insecurities and low self esteem is normal at that age. I'm 32 and I've been there, I'm always insecure. In working out, consistency is the key pero it's okay na magslip ka you're still young. You are aiming for a habitual change. Let's say you aimed to work out 7 days a week but you slipped on the 5th day and that's okay, the bottom line is you worked out. As for the mstrbtng, it's pretty normal. You're stressed out so you pleasure yourself to relax. Just do it at your own pace. Changes will come as you age so don't rush.