One of the bolts was loose and fell out while i was driving, i have an 89 gta and its the bolt holding the bracket for the alternator, top left bolt. I need to know asap that came off loosening alternator a little bit and my serpentine belt broke off, i am not sure how long after it became loose that my belt broke.

Those bolts on the serp setup are all the same pitch and thread - might be 1 or 2 different lengths, but all same pitch and thread - just pull another one out, take it to harware store, and match it up.