My husband was the same and he only really "got it' (although it didnt' last long, he soon forgot) when I said it felt like I had the WORST hangover for 17 weeks straight, 24 hours a day. That put it in his terms! (even though he's not a huge drinker) but he understood then how awful it was. Maybe thinking of some things relative to him. Heartburn, hangover, tummy bug etc. I dont think they ever get the whole body changing thing though and it might be easier to think he wont get it but to get him involved. I had DH read up on reflexology and he gave me a foot massage each night (mind you he only did that with DD not DS.....ggggrrr) but it made him feel good to have found something that would help (he googled it and found the pressure point on the foot that would help my sore back...).
Good luck and hang in there. xo