My cat keeps biting an licking same spot?

The other day I noticed a spot on my cats belly down by his back leg on the left side...ik it's not really belly but idk how to describe it cause its not the leg area...but by it...anyways, he keeps biting an licking it. Over an over again. I wanna know what caused it. He does not have fleas so ik that or a fact. He's an indoor cat. I noticed it got worse tonight. I moved today an when we moved him to my new apartment he got scared I guess an peeed on me (I was holding him) an so I have him a bath cause he smelled like pee an it was gross...I'm not sure if that's why it's worse now cause when I gave Him a bath or got worse or what? I'm tryin to get him to vet sometime next week just to for a check up to make sure he's healthy an everything so when I take him I'm gonna ask about it but I'm kinda worried about it an curious as to how he got it an why he keeps biting at it. I heard it could be from heat spots or whatever there called or anxiety but I've never heard of a cat having anxiety before lol idk. Please help me! I'm really worried :/ thank you I. Advance