Ammonia Clear is not the same as water conditioner. In fact, you should not use Ammonia Clear, just change the water. Chemicals can be harmful so don't use them if you don't have to. Ammonia can be removed simply by doing a water change.
2.5 gal tanks cannot cycle. They are too small. You do not need to add all those cycling chemicals.
This sounds like either ammonia poisoning, swim bladder disease or failure to use water conditioner... Are you absolutely positive you used the water conditioner during the last water change?
To treat ammonia poisoning perform daily water changes until he feels better then continue to perform increased water changes. In a 2.5gal, do one 50% and one 100% per week.
Since he is having trouble swimming it could also be swim bladder disease. You mentioned feeding him a freeze dried blood worm? Freeze dried foods and pellets that are high in grains can cause constipation, which leads to trouble controlling the swim bladder. Fast him for 2-3 days to see if that helps. If you have epsom salt, use that at 2tsp/gal INSTEAD of Aquarium Salt.