Lethargic Dwarf Gouramis

[Essie]

I have 2 lethargic Dwarf Gouramis that look as if their tail fins have been nipped. I have with them a few neon tetras and guppies, couple each of mollies and platies. Any advice please on how to make them less vulnerable or happier?
I had been feeding them too much and the ammonia level was too high - would this have been the problem? My plants haven't grown much yet so is it perhaps because they haven't got enough cover?
TIA

 

[Aiken Drum]

I think the ammonia is the elephant in the room. Ammonia should be zero. If it isnt, your tank isnt cycled. Do you know how to cycle a tank?

How long have you had the gourami? How long has the tank been set up? What precisely are your water parameters? Preferably before a water change.

Fin nipping usually looks like nice, fresh, clean wounds. Fin rot would look more mushy and will come on more gradually?