When I was born I barely slept for the first 40 days of my life and barely had anything to eat, every photo had a ray of light even though the camera had no flash.
Another time when I was about 10, I was laying in my bed, reading something when my legs started twitching, going up and down and hitting the bed, they had a mind on their own. It wasn't until my mom said something that it stopped.
I started having strange dreams of a man in a dark room on repeat for half a year and until I told my mom he kept showing up.
She is convinced I had a demon around me, and she's afraid that it is still there, connected to me evr since I was a baby. What are your thoughts? Is it possible I was cursed or something?
Honestly it's highly unlikely you have been cursed.
Babies not sleeping for a while is relatively normal, leg twitching could be something as simple as restless leg syndrome, sufferers often feel that they have lost control of their legs, and they are moving independently of them despite trying to not move.
Dreams can mean a lot of things, if could be your subconscious trying to tell you something and you have not yet determined what it is. If you are worried I would start simple with a cleansing of the space/home and a spiritual cleansing of yourself, but honestly, demons don't really bother with people under most circumstances, they have their own existences, so it is likely not a demon.
First, I believe we should consider the possibility of you suffering from Parasomnia as a child. This is usually nothing to worry about as it is common especially for children. Usually, Parasomniac experiences resolve as a child grows up and does not require any sort of treatment. So, most probably, you should relax. In case you want to feel more secure, you should use o protective spell on yourself and even learn a banishing spell just in case you get to experiment this once again and in a very direct manner. But, as I said, most probably it was just a sleeping disorder that is very common for children. :)
Like the others said, it's almost definitely just a medical issue.
However on the super off chance that it IS a curse, I've read before that there's an old belief that people can accidentally curse each other with jealous/spiteful glances, and one of the things it can affect is babies. Like if someone glares at someones baby while thinking, "I deserve a baby more than they do. I hope something bad happens to them", the baby could get cursed. Back in the day, people used to put their babies in girls' dresses to keep this from happening because girls are supposed to be immune to it. Franklin Roosevelt's parents did this! Anyway, that's where the term "giving someone the evil-eye" comes from. I just thought that was interesting.