WTF is going on with me?

I don't understand myself these days. 

I few days ago, I had sex with a man for the first time in years... And felt fundamentally uninterested. Yesterday, I had my ex-girlfriend Elle naked under my hands.. And I wasn't particularly horny from that either. 

Elle and I haven't done anything other than short conversations and the occasional hug since January last year. I knew I needed time for my feelings for her to die, before we could be physical again. And they have died. We talked about it yesterday, she doesn't have any feelings for me either. 

We met in Novice' apartment, since Novice is on vacation this week. After having some dinner, and Elle getting a quick shower, we did some shibari. Elle said that she was basically up for anything that wasn't regular piv sex, and she remained naked while I tied her up. I wore just my underwear.

The shibari itself felt very technical to me, since I was practicing a tie that I don't know very well. After having done that tie a couple of times, I spanked, tickled and pinched her a bit. (Enough that she was sore afterwards, not enough for serious bruising.) I also bit and kissed/licked her neck and the lower parts of her stomach. Once I'd untied her, we lay cuddling and chatting for a good long while, limbs wrapped around each other. 

I could have gone a lot further, had I wanted to. I could have given her oral. I think she might have been up for getting fucked by me, as well. I could probably have requested oral from her, or some other sexual touch. And I just... Didn't feel like it. Biting and licking her, hearing her moan, it made me slightly damp.. But nothing more than that. Cuddling was nice, sure.. But only "nice", nothing more than that, which also felt REALLY weird.

I tried to analyze, in the moment, why I didn't feel like taking it further. I concluded that it's because I don't trust her. It seems to me that her reactions, especially her moans and other sounds, are... Fake. Or exaggerated. Or.. Maybe that I just can't read her well enough to be certain. 

Now, I'm fairly certain she enjoyed herself. She mentioned that Liberty isn't really into shibari, and she's missed being tied with rope. She also said she enjoyed the pain&pleasure I gave her, and I believed her words. I believe her intellectually, but maybe not.. Emotionally? Why should that even matter?

I really have no idea what this is. Low testosterone levels? I just got a new shot last week, they should be on the rise. Or is it the ultimate "I adapt to my partners"- kind of thing? Novice is demisexual, so my brain is making me demi too? If that's it, why didn't that happen with Cord? He was demisexual as well. That theory doesn't make any sense. Besides, I'm more independent, more "myself", now than I've ever been. So that theory can't be right.

Is it related to autism, to unmasking? Do I dare to feel my uncertainty more? Or am I projecting my own insecurity, my own fear of rejection and not being good enough? So it's lack of desire, caused by anxiety? Or by being somewhat aware of that anxiety?

Or am I just.... Tired? Overwhelmed, burned out? Slightly depressed, maybe? Depression has reduced my sex drive before. 

I really have no clue. WTF is going on with me?