BIG over shove in NL hi/lo $200 game

[GaZaZaZa]

i generally dont play this game NL and so most of the players are new to me and i have little or no notes on them... have only played 20 odd hands and apart from a few pre-flop shoves no one has gotten out of line and dont have any real reads on villians... but decided to give it a crack and kinda got stuck in one spot.... its 9 handed and my stack is $220

i have a-3-3-5 with a suited ace..on the cut off 3 ppl limped so i called, both blinds come along so $12 on the flop...

flop comes down 3-7-8 two diamonds, i have no diamonds!...
its check to me and i bet $10, BB calls,, and utg SHOVES... he has over $400 also the BB who called covers his $400 bet if that means anything....

Normally in a pot limit game id at least call this(if not re-shove) and then re-asses on the turn.... but i got really stuck in this spot given his massive overbet, especially that the BB is still to come and he covers his 200BB shove......to me it looks like either a-2-5-6 with a diamonds.. or just some shittty top set

i decided to let this one go.. what do u guys think???