Don’t understand what happened
My girlfriends mom kept this betta fish for a little over a year and a half. They kept it in a 2 gallon bowl with no filter or heater. I took care of the fish for a week while they were on vacation, and learned that his living conditions in the bowl were very poor. I really wanted to give him a better life and they did not want to put him in a tank so I offered to do it myself. I did lots of research and went out and got a 5.5 gallon tank with a heater, filter, driftwood, live plants, everything a betta needs. I know you need to cycle a tank before putting the fish in but I couldn’t stand to keep him in the bowl so I put him in the tank and made sure to acclimate him slowly by floating him in a cup on top for 30 minutes. I made sure to keep the ammonia low by doing water changes every other day. Fast forward a week, and he hasn’t eaten a single pellet of food. He has been extremely lethargic and barely moving at all since I put him in this tank, spending all his time hiding. At first I thought he was just taking time to get used to the new tank, but after a week I knew something was very wrong. The first 2 pictures were him in his bowl, and the next 4 are him after a week in his new tank. After looking into it I fear he is very sick and won’t make it much longer. My girlfriends mom thinks he would have just been better off in the bowl, and thinks she was taking great care of him to begin with. The situation is making me feel very guilty. I tried giving the fish a better life, but to her it seems like giving me the fish was a mistake.
Please help me understand what went wrong, and if there is anything I could possibly still do.
I am planning on getting a new betta of my own for my tank I made. I would hate for this to happen again. I just wanna be able to give one a good life.
Please give me advice!!!