Your boyfriend - younger by you by one year and you find him
childish - this shows that the unconscious barrier of a older
woman, younger guy hasn't really bypass you.
What do I mean?
If you bypass this mental barrier together - you wouldn't have
thought of it has *he* being younger, therefore childish. Think
about this, if lets say he is childish - an aspect that could be
discover even as a friend, unlike possessiveness where only being
together would reveal it, in the first place why did you accepted
him? In any case - your heart falls for him, but your mind hasn't
been subdue yet. You thought of the time spent together - wow, its
one year and feel reluntant to release this relation. Yes, I know
you do love him for who he is, but the mental barrier is still
there and you don't realise it. 
His possessiveness is choking you and you feel breathless. Since
now he already break with you - he initiated the break, the
argument is the catalysis that sparks this break - which means you
are single now and seeking for people's advice if you should ask
for a patch or be heartless and kick him out of your vision forever
and ever - one good solution is to *wait* and see if he does
anything since he is the one who initiated the break. If he feels
that it was partially his fault for the raging argument and comes
back apologising and wants you back - and *IF YOU* also wants back
the relation - this is what you MUST do.
1) Psycho and influence and *prevent* youself from having this
thoughts - he is childish because he is younger than me. In your
mental unconsciousness - you have to also accept him, not just your
consciousness. 
2) Communicate and let him know that he is possessive. After
letting him know, speak and work out a solution together. If he
still insist on his own way of thinking and working, say goodbye to
him - he is not willing to compromise - an essential in a relation
- so nothing could stop you from leaving except good
memories.
For example: Maybe can go clubbing once a month, go out with
cousins and classmate is alright, at times when have to come home
late when bo bian one its ok, since you don't do it everyday, kind
of thing.
He *has* to realise that what he is doing is killing this
relationship - then only with proper workable solution can the
relation gradually improve and grow like its potential could allow
it to be.
Cheers
