HELP! Does anyone know what this is?

So my brother's cat scratched me (he usually lets them go outside) and it was after the hurricane irma hit it left us without electricity for a whole week so my house was really hot and the scratch got infected i treated it but pus came out of it the next day along with pain and swelling i cleaned it after all the pus was out or so i thought i kept putting antibiotic cream in it the swelling went down and it the little layer thatcomes out when you cut yourself came up (im not sure what its called sorry) but it was really black it freaked me out a bit it was still red around and the edges of my skin where peeling off kind of like a bad sunburn anyways i decide to peel the hard black layer off and saw that it was a bit hollow likthere was a hole underneath it a bit of pus came out i cleaned it and added more antibiotic cream and this is a day after it itches alot and it worries me how it looks still has this happened to you guys before is it normal should i worry