KatieG, sorry about your gecko. I'm not a vet, but I have 2 leopard geckos, age 11 and 9 years old, purchased from a private pet store (now unfortunately out of business) and a pet store chain. My first two leopard geckos came from the same chain store and shortly after we bought them they...
Some thoughts: I have 2 leopard geckos and they both have different personalities, so it's possible your male has a strong sex drive and is rubbing himself against the tank. If this is the case, maybe switching to a sandy substrate might help? Dry paper towels can be abrasive. Also, I try to...