Is it normal that i feel like i’m dreaming?

Hey guys. So I’m going to tell this story from the beginning, but I’m in no way self diagnosing myself with anything. So today is Saturday, and on Wednesday I started feeling... strange. I was having trouble believing the people around me were real people with real emotions. I was having trouble believing I was real too. I mentioned this briefly to my friend who was with me, but she didn’t really understand what I was saying. I was in class, and after the class ended I felt normal again, and I didn’t think much of it. I had felt like this before, about a year ago and it lasted a couple of days but I didn’t think much of it at the time. I kind of kept feeling like this on and off for the next couple of days, but it wasn’t causing me any problems. But today, I went on a walk with my friend and there was definitely something wrong. The whole walk I felt like I was dreaming. I’m not a very emotional person but I was feeling quite emotional, but somehow my emotions felt fake. It was so weird. Everything around me felt fake. It was a lot more intense and disturbing than when I felt like that on Wednesday. Another think worth mentioning: I started worrying that I was in a coma and that I would wake up as someone completely different. That was the part that bothered me the most. It was so weird. I think I may be experiencing some form of derealization, but I never experienced severe trauma as a child, I’m not easily stressed and I haven’t taken any kind of drugs or anything. A site I looked at said certain personality or genetic traits can cause it, but my family is very secretive and I only recently found out my grandmother was in an asylum at some point. I wonder if she ever had the same thing I’m experiencing? I also was selectively mute as a child, meaning I was completely unable to speak in certain situations due to extreme anxiety. I was never diagnosed with selective mutism unfortunately becuase my family don’t believe in therapy and I never visited a professional about it. But I was definitely selectively mute, which is a big sign I had selective mutism. I’m wondering if selective mutism and detealization disorder are connected? Writing this has helped me come back to reality a bit, so I’ll hopefully be fine soon but if anyone who has experienced this understands what I’m saying could you please inform me on ether this could be serious or not? Thank you very much :)