Struggling with Multiple Identities and Memory Loss

So a lot of my friends say I act differently depending on which nickname I'm going by. I didn't even notice it much. There are some people who say they know me and I can't recall them whatsoever. like they can tell me their full name or nickname I called them, show a picture of them or both of us together, or show me screenshots of texts between us, and/or say what we've done together and I still wouldn't remember them at all. I'd feel so bad that I'd pretend I know them. sometimes on accident I would call myself we by accident and have to correct myself. Sometimes I'd Dissociate for an hour or so and when I open my eyes I'm just like "what". Once in awhile if I think I'm asleep and someone "wakes me up" I feel like I have multiple heads in one and/or more than one mouth and it'll be hard to move and speech feels forced and everything would be blurry. My besties (a system) thinks I might or is a system but I don't know I keep just saying and arguing with myself about it and don't think I do but also unsure that I don't.