BAD RASH, please help.

My 3 month old started having a bit of a butt rash. I started keeping a closer eye on his diapers(assuming that they were being left on too long) & applying diaper rash cream after every change. It would start getting better & then all of a sudden be bright red again & just continued to fluctuate. I just went to change his diaper & now in the crease of his leg he has a terrible rash. But it looks more like post I had seen about rashes caused by diapers. There is red skin & he has a lot of peeling, it looks painful, though he hasn't fussed much. I have pictures but I wasn't sure if I was allowed to post due to the rash being so close to his little boyhood. I would call the doctor but they're currently closed so if anyways can help I would greatly appreciate it! I don't want my little prince to have to endure any unnecessary pain.