TMI bum picture

Charley Knows • 24 and living without a thyroid 💪🏼
Apologies for the TMI but I'm pretty sure I have 'nappy rash'. No I have not been wearing nappys it's just the easiest way to describe what this is. I've been using sudo creme at night but it's still causing me loads of pain. It doesn't itch it burns and feels very hot. It's in such an awkward place and I can't not wear panties at the moment as I'm having to use a pad. It's at the top of my crack no where near my bum hole. If anyone has any suggestions on what to do to make it go away or if I need to see a doctor that would be amazing. Also apologies for the pictures I couldn't get a good shot but hopefully youll see what I mean..... it's been here for 4 days now. It's in line with where my hand is. 
The bottom two are with my bum cheeks closed and you can see the really red bit on the left cheek. 
The pictures don't do it justice it is really really sore. 
Just to add, no changes in sexual partner, no STI's.