> Knowingly going into a relationship where I feel much less for my partner than they do for me strikes me as wrong and possibly manipulative.
It's likely that your feelings will end up much stronger than your partner's at some point... see The Two Step: The Dance Towards Intimacy.
Wrong? You're both going to be learning how relationships work at the same time. Feelings will be hurt. There will be sadness and joy. You're both going to make lots of mistakes... and that's okay.
It's only manipulative if you're intentionally withholding information to manipulate the other person. Let them know about your fears... how you're worried that it will end up being manipulative. They might have the same fears as you.
You're getting a bit of a late start and that actually puts you at a disadvantage. They're going to have skills that they learned from experience. You may actually end up as the test subject. :)
Focus on what makes you happy... enjoy your life... this is the only one you get.
“There is no way to happiness, happiness is the way.”
– Wayne Dyer
I also agree that most research papers I have read generally mention an increase in libido, pleasure, and general euphoria ('recreation' and medical use doses can be the same, as I have read); but I feel none of that. My overall libido was higher than my SO, but lower while on xywav, so it isn't solid experience for all patients.
I agree there is a lot of interlocking stress and frustration in the subject. Bringing up the topic too often, or mentioning frequency, might lead to a 'pressure' on the other person which decreases the spark to try. 'we did Y already Y times, what is enough?'
Sometimes, there can be some negotiation, 'If you are not up to full sex, can you do these alternatives? Can I touch or look at you while I do things, myself?' Sometimes getting to bed earlier can give a little extra time for one partner to feel relaxed enough to be in a better mood.
One book that helped in our relationship was "The two step." (ABE books has used copies, but I've given an Amazon link) The idea being sometimes in a relationship, there are people who 'seek' (want more), and some people are being 'sought' (want, but less often). Sometimes in the run together the catching part is fun for both; but if the 'seeker' gets too enthusiastic, the 'sought' creates distance. If that distance stays for too long, the seeker stops seeking, which isn't good for either side. A good balance is when the seeker knows when to give some space, and when the sought turns around and becomes the seeker for a bit.
https://www.amazon.com/Two-Step-Dance-Towards-Intimacy/dp/0802130321
A couples councilor might be a step in the future as well; but that's a book recommended to us during a session. I wish you both the best of health in body and mind. I've struggled with a similar situation.