Help ASAP~!

Ok guys, i was riding home from work in the rain. I have about a 45 minute drive and today it was raining...well the fuel light came on so i decided to fill up, i guestimate i had about a half a gallon left...Get back on the highway and go...i get off of the highway about 20 miles later...get to a stop light and go tot ake off...she dies...start her up and have to rev to 5 grand to take off and she is doggy!! i mean little acceleration...and it would get jumpy go from doggy to fast...then it just went to a complete dog...could i have gotten bad gass?? i usually put midgrade in and got 87 octane in it this time. I have ran 87 before without problems, but not this time....COuld the weather have affected it?? i need help asap guys, thanks!