Just feed him 1 medium adult mouse every 5-7 days. That's what all of my 07 babies are on and they are growing just fine. Believe me, they can handle it. I even have an 07 Spider female who has some congenital defects in her neck, making it shorter than normal, and she still strikes, coils, kills, swallows and digests her adult mouse perfectly fine. She's still under 200g.

The fuzzy mice are generally left for corn snakes and for tiny baby ball pythons who have just hatched and need a smaller meal than a hopper or who need to be assist fed. They really don't offer much in the way of nutrition and your snake is using more energy eating and digesting those two small mice than he is getting from them. Most of my babies that hatched last season(18) were started on live hopper mice or larger and did great. Two were under 50g in weight, and didn't eat for 7 weeks so they got assist fed for a bit until they got the point

Try a bigger mouse every 5-7 days. He'll be fine.