Rash Help?

I’ve had a weird pain in my upper thigh for about 4-5 days. Felt like a deep bruise over an area of 1.5 inchX0.5 inches. It was only irritating me first thing in the morning or when I did something physically active. (No bruise was ever visible)

Today, this rash showed up in the same area but obviously over a much larger space. And it HURTS. Zero itch whatsoever. Roads are bad here so I don’t particularly want to make a trip to the doctor tomorrow but I’m wondering if anyone knows what this might be or home remedies I could try for the time being. (Currently enjoying an oatmeal and baking soda bath in the hopes that one or the other will help 🤷‍♀️)