You are going to want to get rid of those fish. Damsels are the meanest fish you can get in the hobby, and they will more than likely kill anything else you add to the tank and you are probably going to end up with one. Plus you are limited to one fish per 10 gallons and you now have two of your 3 fish.
Also, you should only add one fish at a time, with at least 3 weeks between additions. This is especially important with newer tanks.