hmm...i think first of all you do have some self confidence problems..i think you realize that as well...do something for yourself..if you aren't happy with your weight go to the gym..it'll help with your depression as well since working out releases endorphines..sort of a natural high your body gets and you feel good
as for the phone thing...i will say that if this is a new development then yes there could be something fishy goin on...this is just from my personal experience...my boyfriend and i have been dating just over 2 years now, but just after a year into our relationship he started getting weird and possessive about his phone..as you said..which he NEVER was before...so..i snooped...couldn't take the weird behavior anymore...well...found out he was sending some really inappropriate messages to a coworker of his...i was LIVID...we nearly broke up, and honestly to this day i still have a few trust issues with him...he never cheated on me, him and the girl never even hung out(i had actually put her number in my phone and texter her later about what he was up to)but he knows that what he was doing was out of line and inappropriate...we worked through things, and since he never did cheat on me i let it slip but told him if i was ever disrespected like that again then it was over..i dont send that crap to guys so he has absolutely no business texting this chick..ugh..thinking about it now absolutely infuriates me...anyway..things are much better now..i trust him...he knows if he ever did anything i would most definitely find out about it sooner or later...and things would be over this time..i refuse to be in a relationship with a man that i gotta keep tabs on..i dont wanna worry everytime he walks out of the house worrying about where he's goin or who hes with...i got my own crap to keep up with...
anyway..while i dont encourage the snooping..i don't believe in staying in a relationship thats fake..for me, my gut feeling was right..my bf was being inappropriate...and i'm glad i found out..and i'm glad i put my foot down and we worked through it...theres really no way of knowing why your boyfriend is being the way he is...it could be the fact that bc you dont trust him he's being weird about his phone...maybe you really have nothing to worry about...but no one here can answer that for you...