Hang in there mate do not give up!
I like Tainojim's approach a lot.
Try to relax a bit, it is only drumming, ha-ha.
Even experienced drummers go through exactly the same thing when they start out with a new/other band, I speak from the actual facts that happened to me!
Also, generally the band will understand and they will be accomodating, as long as you put the work in, just keep it extra simple in the beginning.
Good luck, Cheers and Happy drumming,