"sex life used to be great. He always put my please first, went down on me all the time and it was stunning."
"as for oral. I don't know why, but I've never liked doing it. I did it when we first went out. (my husband is the only man I've. . . Well you know, orally pleasured) but I never liked it."
He went down on you all the time and you gave him the odd blow job when you first went out and then stopped because you never liked it.
Sounds very one sided, doubt many men or women actually enjoy the act of giving oral but it's about making the other person feel good and reciprocating particularly when they've been very generous to you.
Not just unreasonable for not trying to do something about your lack of libido but also potentially unreasonable in how one sided your sex life was when you were active, at least that's how it sounds from your posts. Can't always receive and never give!
But you need to rebuild step by step, whilst he sounds lovely and very patient, he's only human and it's unreasonable to expect him to put up with this, unilaterally without any discussion or effort to get back on track.
If you enjoyed sex before, chances are you will again. It's like jumping into a pooling on a warm day, don't dip your toe, you'll tell yourself it's too cold and you don't fancy it. Jump in and after initial fuck it's freezing moment, your body adjusts and then it feels amazing...