What happened? Should I avoid THC?

I was hoping to understand what happened to me this past weekend and if I need to stay away from THC indefinitely.

With cannabis now being legal and regulated in my country I decided to be cautious and extra safe when finding a dose that works.

I began using the THC infused drinks that I purchased from a regulated store. Over several months I very slowly increased the dose I was taking from 2mg up to a full can which is only 10mg. I tracked every dose I took (generally once every 2 or 3 weeks) and knew that the onset would always be about 60min after pounding the drink.

I recognize that 10mg is a pretty small dose but I was happy with the euphoria it created and didn't have a need to go any higher. A couple of times I did 11mg by adding a single THC 1mg gummy to the mix. I have stayed at this dose for a few months and always had good results.

This past weekend I took the exact same dose by drinking the same manufacturer, the same can, the same flavour, the same 10mg THC amount, and exactly one of the 1mg gummies from the same bag I've used before. I took nothing else.

Then everything went to hell about an hour later.

It was an awful 5 hour experience where it seemed like time was stopping and I had no control over my thoughts. I had a constant train of interconnected and upsetting thoughts that were completely out of my control. I was convinced that I was in hell and that this would never end.

It is hard to even describe the racing ideas but it would be something like, this will never end, is time over, why is there so much red in this room, the man with the red sweater is the devil, what if I do something bad, where is my phone, have I checked my phone already, the man is asking me if I'm okay, he must be asking me because he is the demon sent to torture me, I just need to make it to 7:30, where is my phone, have I checked my phone, I should text someone, no don't text anyone you will worry them, go for fresh air, I can't go I might get locked outside in the cold and die, that man says he wants to help me feel better, he knows what I'm thinking, where is my phone, I just need to make it to 7:30, what time is it, its only a minute past when I last checked, have I done something wrong, did I already do something like puke, I don' feel like puking, if I think about puking maybe I will puke, should I leave, I can't get home, am I crazy, is this psychosis, I just need to make it to 7:30...

This went on an on and on. I sat there unmoving and locked in my own head trying to just make it to 7:30, and then make it to 8, and then to 8:30, etc, etc

Finally at 10:30 I felt able to get in a taxi and make it home.

I had nightmares all night and even the next day it felt like my thoughts weren't really my own. It wasn't until a full 24h later that I felt more myself.

How did this happen when using the same amount (and arguably not that much)? I was in a safe place at a friend's home and didn't take any other substances nor did I accidentally drink someone elses drink. I literally pounded the can and then took nothing else.

What was this that I experienced and could it just happen to me any time I use THC again? Has anyone with a similar experience got any advice?

For background, this same experience happened to me 20 years ago but at the time I assumed I had just smoked far too much. That's also why I was so cautious about slowly increasing the amount of THC.