Bum spots plz help!

So about 2 weeks ago I got spots on my left bum cheek and they weren’t painful or big and I thought they’d go away. But this week they’ve gotten bigger and they’re sore and red, I’ve no idea how to get rid of them! Are they just from sweat and wearing tight pants at work ? I’ll attach a photo so sorry for tmi but I’m embarrassed to have sex with anyone because it looks really bad! Plz help If you’ve experienced something similar 😅