feeding will go back to normal when the snake is ready. your job is to try, if it doesn't cooperate, then it means he doesn't want to eat.

you can try f/t mice, but what will you do if it refuses even the mice? perhaps you'll entertain the idea of feeding live, then if it refuses even the live food, what next? trying too hard will add more to your worries when your snake doesn't want to eat no matter what you offer. i learned this the hard way. the best way to solve snake feeding issues is ideal husbandry and simply wait them out.

p.s., i think your snake just hit the so called "wall". this happens sometimes when young snakes are fed more than the ideal. they eat well and grow quick for the first few months or so, and then suddenly stop eating when they reach a certain age/weight. it happened to two of my snakes, not my doing mind you. i got them from somebody who enjoyed feeding the snakes, when they started refusing food, the owner panicked and wanted to get rid of them. i bought them for a song because of the off feed issue, and after a few months of fasting they are now back on a regular feeding schedule.