I didn’t even understand what happened

Hey guys, today I had an experience that I have no idea if it’s normal. It was half scary half mind blowing. I’m hoping someone experienced to help me understand what happened. This will be on the longer side of posts but I have to describe what happened as I’ve never seen anything like that in videos.

That being said, I am really new to all sensations, spasms, twitchs and whatever else a prostate massager may give. It’s a whole new world for me. I don’t even know if I had an orgasm (if it was it was several). I didn’t ejaculate for sure. But I don’t know what it was. Here it goes:

I was laying on my back, then I decided to clench my butt and held like that. When I contracted both my PC and sphincter (for what I initially expected to be no more than 30 sec) I started having spasms and my head was trembling (like a time lapse of someone sleeping). Because my butt was clenched I didn’t feel as tired and I could hold my muscles for longer. Soon my whole body was twitching and my hands were shaking vigorously. It felt really good.

but then things got weird.

As I continued holding and clenching my hole body started to contort in random ways. It was like cramps, but it didn’t hurt. My feet contorted involuntarely to opposite sides, while my wrists were bending in a way that my rigid fingers pointed to the inner part of my elbow. Both my knucles were touching. I had absolutely no control of my body as my mind was in what I can only describe as in another dimension. I only gained consciousnes when the stretching muscles were in my limit and it was starting to hurt. I only had some sort of presence as I was half scared and didn’t want to hurt myself. At this point I stopped clenching/compressing and got back to normal. But I was hooked on that feeling and started again right awat. Back to the whole thing again and different random contortions. My abs, or my back, my face. I was half scared the whole time, but I just couldn’t refrain myself to go back to that state, as it was almost immediately.

I was like this for a good 10 minutes (maybe more, maybe less. I was watching a porn video on the VR when I started. I was somewhat in the middle when the VR slipped off my head due to contortions). I only stopped because my biceps and abs were really sore and at this point I was actually freaked out.

Even after taking off the aneros, but my arms specially my hands were still twitching (I was feeling some sort of staggering).

I never felt anything like that. It was not as intense as a ejeculatory orgasm, but it was long and uncontrolable. I felt very horny and it was like I was humping my bed with my whole body, as I was half counscious the whole time. I definitely felt good as I repeated the whole thing at least 5 times. After I was exausted I didn’t feel horny anymore and I was satisfied as I usually am after cumming.

If you’re reading until here, I’m sorry this was too long. But I’m hoping somebody knows what this is. Was it a dry orgasm? Can I hurt myself while having my session? I would like to let go of being scared and just enjoy next time, but I would like to know what this is before that haha.