Nostophobia is feeling scared or uncomfortable about the thought of the past, like things that happened a long time ago or things that you used to do. It's kind of like being afraid of old memories or looking back in time.
It's like when you remember something that happened a while ago and it makes you feel sad or scared, but you're not sure why. It can happen when you see something or smell something that reminds you of the past, and it can make you feel really anxious or nervous.
For example, let's say you used to live in a house that had a certain smell, and when you smell that same smell later on in your life, it reminds you of that old house. If you have nostophobia, it might make you feel very scared or nervous because it brings back those old memories.
Nostophobia can be hard to deal with, but it's important to remember that those memories are just part of your past and they can't hurt you now. It's okay to think about the past and remember things, but it's also okay to focus on the present and the future.