why is my boyfriend/ best friend doing this to himself?

okay so der was a new guy who joined our school last year, but only in a couple of months he left d because he wasn't fitting in, i was one of d only close friends he had at that time. for a year we had been close, we became best friends, i helped him with his studies, we killed zombies on xbox, talked about comics, we were just like each other, we had lots in common...

den this summer he proposed and i said yes...at first both of us were feeling shy but we got over that period and we were doing great together, i still came at his place to beat him up in mortal combat, we had yo mama fights and we fell in love with each other very deeply...

but then 2 months ago our exams were starting so we went underground fro studying

both of us are avg students, the kind who want to prove something of themselves

so we studied hard and just after our exams ended he had to go to london

at the exam period i got a feeling that he was avoiding me, he didnt pick up my calls, said that he'll call in a while but he never called

i forgot to mention that his parents got divorced a long long time back and his mother was a beautiful single mother who full filled all his needs

just a couple of years ago she got married with another person... but he liked his step dad

he had always felt uncomfortable to tell his feelings about his family matters so i still do not know clearly what happened with his real dad who he still meets occasionally

so for the whole month of September we didn't talk much, we had decided that before he goes to london i will come to meet him at at d last second he asked me not to....

i begged him to tell me what has happened

all he told me was that he needs a break from everything

so i thought that he needs time for himself so i said k

i told him im always der for him if he wants to talk about it

then he went to london without a goodbye, he said he might move to london permanently with his grandparents....i knew he couldn't do that midterm his mom wouldn't have allowed it

he told me that he'll come back in october end

for a month he had left for london...the only way of contacting was online but he had deleted his account...so for another month there was no contact

even on the day of his arrival he didn't return which scared me...i thought he wont be coming back

but then he returned in november, i was relieved

the whole month i was anxious to know if he is alright and over his depression

but the day he returned he broke up with me

everything was going great i didnt know what he wanted from me

when he broke up with me i couldn't say anything, he wanted us to be best friends, i didn't say no to that but i cried for an hour

i decided not to talk to him for some days...i called him once or twice but he was avoiding me when he only asked me to still be friends

after not contacting him for a long time i talked to his mom online which sounded very worried for him, she told me that its her and his dad's fault

i couldn't understand what really was happening

so i asked him directly

but he got mad he started begging me to leave him alone and stop asking questions

i didn't want to bug him so i went offline

i don't understand what happened, he is not ready to tell anyone

i thought that i should leave it and move on with life

but if your best friend would have been going through such pains you would want to help him too

i don't think i should leave him alone like this

or should i?

i was the only good friend he had for a long time

and now he acts like m just some annoying girl whose irritating him

what should i do? please help