Hi! So I have had my betta fish for around 5 months, and he has been perfectly healthy. Recently, around 6 days ago, I noticed that he had a hole in him that is clear through near the back end of him. I was quite distressed because I had not noticed it before, and I look over him each day. So I read online about trying melafix, so I went out and bought some and followed the directions on it. I have used it for the past 6 days. There has been no improvement, and he has stopped eating. He used to swim around a lot, and now just lays at the bottom of him bowl. He lives in a 1/2 gallon fish bowl without anything fancy in it. Does anyone have any suggestions on how to treat my fish??