I have a Betta who is ~4+ years. He’s been laying on the bottom of his own 10g tank for a few weeks, I have tested, salted, medicated, reduced water so he didn’t struggle to get to the top, finally moved him to a small 1.5 g so I could focus in, to get him food, made a black water tank & he’s just not improved. I think the humane thing would be to euthanize, but it’s just so difficult to actually do! Either way I feel terrible. Any words of wisdom?