My ball python won't eat

My ball python has eaten once in over a month. He is very very thin and I'm panicking. When he first stopped eating I thought maybe he was going into shed or something but after awhile he started to lose a lot of weight so I decided to buy a new box of mice. He ate one right away. After that he when into shed. When he came out of shed I realized that the new mice in our freezer had rotted. I believe it was from the bag I put them in that has supposed to keep them cold. I got a new box of mice but he still won't eat. They don't smell bad. I guess I'll go buy smaller mice at the pet store tomorrow and try those?
Please help me I really don't want him to die but I don't know what to do.
Thank you in advance

What is his:

1. Age?

2. Weight?

3. Type of enclosure - size and type (glass, PVC, etc.)

4. What are the temps on the hot side and cool side and how are they regulated (what type of thermostat)?

5. What is humidity?

6. Are there identical hides on the warm side and cool side and are they snug for him?

7. How are you defrosting and how are offering the frozen food?

8. What time of day are you offering?

9. Are you handling him? If so, how often?

Please answer these questions so we can help you and your BP. Thank you.

And how long have you had him? Got any pics* showing his body weight? (*preferably not coiled up, it's harder to judge a snake's weight when they're coiled up)

I got him a smaller mouse today and he ate it!!

Thank you very much for trying to help me

Since you seem to be (fairly) new, I'd just like to make sure your husbandry is in check, so it's optional but having the questions dakski asked would help as a referral if you have any further questions.