Standard questions; how big is the tank and is it cycled? What are your water stats like?
For the moment, I'd be inclined to do a very large water change (do the testing first though ) and not feed for two or three days (along with a few extra water changes, if you can) and see if it improves.
i dont currently have a testing kit been meaning to get one but everytime im out it slips my mind. Its 120 litres roughly. Had 2 and a half week fishless cycle with just plants in and its been running now for a month and a half but the other fish seem fine
yes i was adding ammonia top the tank whilst it hads no fish in the bristlenose has been in there about 2 weeks along with 2 other bristlenose. I also have a betta 3 gold barb and 3 cherry barb which i found out after buying them wasnt enough so will be buying more soon to rectify the fact that they are schooling fish and need more company