Hello! Sorry for another one of these, I'm sure you get tired of seeing them. I'm just really stressed. I've had Zedd for about a month now and he as only eaten for me once (12/15/16). He is a 2 month old, almost 3 month old ball python and only weighs ~90g. I tried f/t for his first meal and he accepted it perfectly. After 5 days I tried again but he didn't seem interested. I left it in the cage overnight and he didn't take it. So now it has been around 3 weeks since he last ate and I'm really worried about him. I've offered around every 3-4 days (which might have been too often :/ ) Live rats are hard to find in my area but I know how to get mice the correct size. Because he already ate f/t I didn't want to rush into getting mice because I am worried about the future problems with switching back to rats. He has been losing weight which is why I'm so concerned.
Should I try mice and take him to the vet if he doesn't accept?
I don't handle him besides cleaning and occasionally weighing. I just want to get him established eating with me.

My hot spot is 90-88 degrees and the cold side is 77-75 degrees. The humidity is usually between 50-60%

Sorry again, I'm just extremely worried for my little guy.