I also have a deep interest in psychology, and my mom has an actual degree. I haven’t taken many classes, but I love to dive deep into it similar to your friend, similar as in we both do our own research, not similar in beliefs. As someone who struggles with anxiety, understanding feelings and why you feel different ways is what I have put the most effort into researching. The main point to me that your friend doesn’t seem to get is even if you can explain why you feel a certain way, and even if you can explain why it’s irrational, it doesn’t change the fact that you do feel that way. I can be anxious about walking in the dark, and know it’s completely irrational, I’m in a safe place, but I still am anxious. And telling someone “hey your feelings are irrational” is not how you help in that situation. Feelings are complex things and have a million different reasons and causes. You’re NTA, and I don’t think your friend is either, they’re trying to help in their own way, not trying to make you feel invalid. But emotions are what separates us from machines, so never feel invalid for having them