UTI help

I've ignored a bladder infection for about 2 weeks and finally went into the after hours clinic last night because the pain got so bad I couldn't handle it. Since it was after hours, the lab was not open to do a urinalysis. The NP gave me a shot of rocephin and a prescription for another antibiotic. Any tips on how to make this go away faster? I'm afraid it's progressed to my kidneys because my back is KILLING ME and I've been in bed all day.