Major Scuba Diving Problem!?

I have to go Scuba Diving next wednesday at the local pool for my leadership cl, but I can't swim! The teacher knows I can't swim and the Instructor who was here just told me as long as I can kick, I'll be all right. I don't really know though. My fear is I go down and I can't swim back up..That would be embarring, or I go down to fast not being able to equalize and I hurt my ears.. Do you guys think I'll have to much difficulty, I mean I will have oxygen! ahha.