The last time this happened it turned into some kind of sleep paralysis where I became aware of my physical body but was unable to move as I crossfaded between dream and reality.
I've had the sleep paralysis and crossfade that you describe. But it's never psychologically unpleasant.
I've also had lucid dreams where it seems like I get stuck in a time loop and keep dreaming that I'm waking up. It feels like hours have elapsed and I've even gotten bored.
This might sound weird but what works for me is once I realize I’m lucid and the dream starts falling apart as you describe it - I quickly start spinning my (dream) body counter clockwise. In most cases this stops the awakening and I can continue lucid dreaming.
Waking up in the ”time loop” is also recurring to me, but a reality check often gets me back on track even when I’m pretty certain that I’m awake (I’m not). I usually just look at my hand. If my fingers look spooky, I’m still sleeping and can induce lucid again.
While I believe this can just happen to some people, in my case it was a result of sleep apnea. Getting diagnosed for it and taking remedial steps has been a life changer for me.
It can be difficult to control a lucid dream, so it may take some work. Most of my dreams have always lucid, but I didn't know people tried to control them until I was an adult. One of the first times I tried to control one, I tried to teleport to a beach, but instead a matte backdrop of a beach popped up, like I was in a 70's TV show.
It's apparently common enough that there's folklore around it: https://en.wikipedia.org/wiki/Night_hag
I've only had the sleep paralysis a couple times thankfully, and anecdotally the last time I had woken up in the middle of the night beforehand, remembered something I needed to do on my computer, took care of it in a dark room real quick, then went back to sleep. I suspect the sudden bright light and a bit of stress probably contributed to it happening.