Is it normal that I still stalk my ex girlfriend on social media
You really shouldn't be doing that. Why are you stalking her on social media?
I feel like she is my whole world, and I'm feeling kinda jealous about losing her.
It is not right to stalk people. You need to move on when a relationship ends and leave the other person alone.
I'm just going to watch her quietly, after all I can't reach out to her.
You shouldn't watch her at all. It's an invasion of privacy for her, and it will keep you from moving on. You should delete any access you have to her, and begin trying to find someone else.