Bad memory What to do?

Hello, I'm 17 years old and still a student. For some time now, I've had the problem that I forget a lot of things and am generally very forgetful. I've had this problem for several years. I often forget where I put my keys, wallet, etc. I can hardly remember many situations, or not at all. This isn't just noticed by me, but by many people around me too. For example, if someone says "Do you remember…" I have to answer "no" in almost 75% of cases if this event hasn't happened recently. I also regularly forget appointments or homework. I have to write down almost everything, like which street I have to get off at if, for example, I only go to the orthodontist once a month. I often forget entire plots in films that I've watched, and then I can only remember the plots very vaguely. Could this be because of my vegetarian diet?

Please only serious answers!

Thanks