I would agree that the humidity is the problem. If he has dents in his eyes and retained eye caps then he's not going to be feeling very secure at all. When your snake is going into shed and he's uncomfortable and he can't see that well, he's moody right? Well that's how your BP probably feels all the time.
I think you recognize the problem and thats great. Winter can be a pain in the a-- for humidity so I would try and ditch the lamp for now (or permanently). Get a good heat source - heat mat - and a thermostat. You can get a fairly inexpensive thermostat called HYDROFARM - it's on amazon - and it works great for one enclosure. It's $30.00. A heat mat may run you $10-$20 so overall, it's pretty inexpensive to get set up properly.
In the meantime, give him some Luke warm baths - put a few drops of baby oil in there to help with the retained eye caps/bad sheds. If he has a lot of retained eye caps and you want to help get them off, there is a non-intrusive way to do this. Just for the record though, I totally don't agree with using tape or pulling them off or methods like that - too many snakes have ended up seriously injured and/or blind and we don't want that. Just get a soft/damp face cloth or a wet cue tip. Put a little baby oil on it and lightly work the skin away from the eye, going back towards the tail. Never pull or tear though. Just try and loosen the skin. I'm not even sure if his eye caps are retained or if he's just got the dehydration dents,....either way you definitely want to try to fix this bc he's probably pretty uncomfortable right now.
Anyways, all the best :-)