TMI!!!!! what is thisssss????

hi so i woke up yesterday morning with a burn in the crease of my thigh and my vag and i took a look at it and this is what it looked like (1st pic). i went commando cause i figured it could’ve been my underwear was too tight or something, so then i woke up this morning and it looks worse. (2nd pic) i just cleaned it really good, i just want to make sure i don’t have some weird sti or something or no infection or health problems. i’m lowkey panicking.