Okay I'm starting to get depressed about this tmi

Here I go, my butt crack has been itching and raw. I sweat during the day so I've been using baby powder to help with that but the itching doesn't go away and sweating makes it worse. There's no bumps or anything major its just red and raw. It hurts to wash it but I wash it anyways and I'm starting to think its a yeast infection. I don't know HOW a yeast infection would be on my butt other than using a public toilet? I mean I use the toilets at work and that's all I can think of. I refuse to use any public toilet I would rather hold my pee that's how much of  a clean freak I am so you can see why this is literally making me depressed, but at work I'm there 8-12 hours a day I can't hold my pee that long. Seriously I don't know what to do. I thought about letting my skin air out so I slept without underwear and there is no difference. The only thing that gives me any relief is the baby powder however it's not fixing the problem at all. It will be a couple hundred dollars for a doctors app but at this point I don't know what else to do. This is really embarassing and its a pain in the ass pun completely intended. I also used diaper rash cream, it gave relief but it didn't help. 

My anus is not affected at all, it's literally my crack. And that's so humiliating to say and I don't even want to talk to my mom about it. 

A doctors visit will probably be even more humiliating. I just want to cry. 

Added: If it is yeast, is there anything I can go buy from the store to treat it? I've read natural remedies like coconut oil and cranberry juice and I'm going to give all of that a try, but if all else fails I want to know if there's anything I can get from the store similar to like Monistat.