Are you in IC? If not, go, if only to figure out the low desire thing. I've had the same problem...and for me at least, it's the courting and the intense feelings of the new and different and hopeful that I like. My H is like vanilla...I like vanilla, but sometimes something less predictable and safe is what I want. And also, for me at least, a huge part of my problems with wanting to be intimate with my H was because the R was bad...I didn't feel heard, didn't get any kind of positive touch except in pursuit of sex, felt like he made me the scapegoat for everything. Voicing my feelings and taking control of my own life and responsibility for speaking up has helped in the sex department a lot. It's not perfect...but there's progress.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712
