Your scores should come up because CCs will have a bal $0......you might take a hit on a new account BUT FICO likes a mix of credit...revolving & installment.
Just do not let you CCs go inactive!!! that will hurt & then when you use them, even for 25 cents you get hit.
Never close a CC (without good reason) just use them once every 3-6 months....the amount doesn't matter.
As I said before...I use 1 to pay for groceries and then I PIF within a few days of it appearing on my new bill. The next month I will use another CC for the same thing or for another that I usually pay cash for. They do not have to be used every month and you do not need to keep a running bal.