This Is Not Much Of A Question Its More Of

This is not much of a question its more of a can you tell me if there is something wrong with me or am I just being dumb. It's been a while now that I haven't been able to concentrate in stuff especially reading things sometimes I have to read over and over and that's not how I used to be in school I used to do a lot better but my grades have fallen and sometimes I read something but then I re read it and it was actually another word like for example "Pistons ...." I read it as Pelicans it's silly but I've messed up in class because I forgot or miss read the problems and I forget to do things that I said I would do. I don't know anymore is it just a coincidence or is there something really wrong with me