My four month old rabbit has fleas and a blue spot on his head. WHAT IS WRONG?!?

I just went in my room && I was going to pet him && I seen a spot on his head.., it was blue it kinda looked like a bruise but I think it's from the fleas. He has treatment being sent right now. I just stopped working., so some home remedies could help instead of being sent another bill. I REALLY love my rabbit, I don't want him to die.. so the vet is an option but I don't want it to be a first choice. He is a black bunny, all of his skin is gray except the spot on his head, it's blue. Please help!!