Help!

Goldfish and gourami's shouldn't be in the same tank for a few reasons. The first reason, you have already found out. Goldfish are better off in a species only tank. If the gourami's are gonna nip their fins, you cannot stop it. Another reason they shouldn't be together is that goldfish are not tropical fish. They need cooler water than gourami's. Not to mention that comet goldfish get up to 2 feet long and really are only meant for ponds. The comet's should be taken back to the store.