FLEAS!!!!!! Help me please

Oh my god, my cat has fleas and I just brought my newborn home a week ago!

Me and my husband have tried so many things but we can’t get rid of them. 😫

We are super tight on money and Im not sure what else to do.

Im about to have a panic attack. I’m postpartum and I cant handle this right now!

Does anybody know the best way to get rid of them, that is affordable?

Or should I burn my house down? 😩😩😩😩

Sorry If I posted on the wrong forum :(

*** THANK YOU TO EVERYONE! You guys are awesome. Wish me luck ❣️***