I just bought A 2 1/2 gallon tank, and purchased a betta they had been in the store for over a year and a nice large tank with fancy guppies. I purchased two fancy guppies and the one betta that was already in the tank with them. He seemed OK in the store but ever since we got him home he’s been hiding and staying very low and I have not seen him eat even once in the last five days. Here are some pictures etc. any information is appreciated. I’m very worried!