He just needs time to adjust and to be fattened up. One or two feedings will help but it wont make up for a month of no feeding especially if this was a normal thing for him from his previous owner. The joy of these snakes is that you don't need to handle them everyday for them to become docile. You just need to get him on a routine and learn his habits.

I would give him a few more feedings <perhaps 1 rat per week for a couple more weeks>make sure your husbandry is correct and temps are good then just watch him. He's putting on weight finally having been fed by you so he will also go into a much needed shed as well. Very grumpy snake time.