If your tank is only 2weeks old I would guess its not cycled properly to support the amount of fish you have.
I also noticed on another thread of yours that you are using bay leaves as leaf litter.
Some ornamental Bay leaves are toxic and could be poisoning your fish.
To be on the safe side, remove the leaves and start doing daily 50% water changes.
I'm all for using leaves in aquariums but I would be careful which ones you add. Some leaves are toxic when ingested and could kill your fish.
Cattappa, banana, magnolia apple, hawthorn oak and beech are all tried and tested and safe.
Indian Bay leaves are said to be safe but unless you know what species of bay you have for sure, I would remove them.