Having your snake not eat in close to 4 months seems like more of a problem then it eating mice. Nothing wrong with your snake eating mice, I feed Curly 2 mice every 10 days or so...
i've thought about going up to small rats but i don't want to go through the hassle of changing prey, and don't have the equipment to keep a rat if he doesn't feed.
Personally i feed live, but it sounds like you feed F/T, but whatever works...if you switched from live to F/T that might be a problem too...
Also i would be wary of feeding your snake mice that you caugt in the 'wild', what if they had some sort of disease like rabies or something that could give your snake, or you an infection?
i would try to keep your snake feeding about every week or 10 days assuming it is an adult.
Reasons why your snake didn't feed might be temp related, make sure you are keeping the proper gradient.

Any ways there are some things to think about. and my 2 cents.

good luck.