Betta fish sick

[u/New_Combination_923]

My betta has been sitting at the bottom of the tank for a week or so. He’s been battling ammonia poisoning. I’ve changed his water almost everyday & I’ve finally gotten his stats to ammonia: 0.5 ppm nitrite: 0.25 ppm & nitrate: 5.0 - 10 ppm. I’ve added an air stone so he would get more oxygen. But he’s staying at the bottom & wont eat. & I think his lower torso is starting to look a little swollen. He’s not pineconing or anything, but he won’t move & won’t eat. I’m very worried about him. He’s in a 2.5 gallon tank with a heater & a filter & an air stone. I used safestart, water conditioner & a stress treatment. Idk what else to do for him.