Please help, emergency with slime coat?

I umed my local pet store was reliable. I was told that I could keep a pleco with my two goldfish, but last night the pleco started attaching himself onto my ranchu. I scared him off several times, but when I realized that the pleco would not leave him alone, I separated the pleco from the tank. Now my ranchu appears to have injuries to his slime coat and is acting more stunned than usual. I don't know what to do, and I have to be away for a few days... I really don't want to lose him. My only idea is to add nutrifina Cycle. Please help!