Hi Libby, yes it is a really frustrating making situation to have to deal with sheets in the middle of the night. For John, I finally got smart and put a plastic cover over the mattress pad, then made up his bed, then another plastic cover, and made up his bed again. The covers can be costly, so even a plastic oblong table cloth with a flannel backing would do, this also helps to cut down on the odor and they can be washed as well. He only wet the bed 2 times, and that was enough for me.....
For your son's attitude about himself, and his failure to do what his father expects and what you want is truly a disappointment for him. The little ones really want to please us, and no doubt it is a nerve of contention for him, and if he is at school, it might also become an embarrassment as well. No offence to your hubby, but backing off and leaving it to you might do you son some good, as he is only 5. This website if you can get him to read this might be of help http://www.childdevelopmentinfo.com/disorders/bedwetting.shtml and has some good information on bedwetting, medications, behavioral techniques etc.
You are doing all the right things, no liquids, waking up before you go to bed. I remember doing this with my son too...3/4 asleep he'd be, and sit him down, then back to bed. Actually, it is now a rather fond memory, because bringing him back upstairs, he'd say "thanks mommy" and be sound asleep within minutes. He was a very deep sleeper.
You do sound terribly upset, and with reason, between a rock and a hard place wanting to protect you son, and wanting him to stop bed wetting. If he is on medications, this can also affect his ability to wake himself. Yes, a visit to his ped-dr would probably be in order, just to check out there are no infections etc. As I read in this article, dr's are not too worried until 6 years.
My dear son, bless him like I said, 2 times was enough for me, never made another wet bed. However, during the day, he would wait til the last second, then fly into bathroom...many accidents. Eventually, I'd had it, so I just told him matter of factly, John when you pee/poop in your pants from now on, you will need to clean up your own mess. It took a bit of time, however less frustration for me, and teaching him action:consequence....he'd only do it at home, not at school, so I knew he did have the control....the adhd made him wait, as he didn't want to leave what ever he was involved with!
Take care, Simba1