How do you know the difference between an anxiety disorder and normal anxiety?

How do you know if your anxiety is just the average level of anxiety that everyone has to deal with, it’s not the most fun thing in the world, but it’s part of life, or if you have a legitimate anxiety “disorder”.

I feel like I kind of walk around with a knot in my chest a lot of the time, and I kind of get worked up about things, not like worrying about the future, but more replaying the past, random things, and feel anxious about them. I feel anxious about social situations, meeting new people, seeing friends that I’ve known for years, I have a lot of separation anxiety. If I go more than about a day without talking to my boyfriend I’ll cry. Sometimes even if I’ve seen him or talked to him recently I’ll just start to miss him so much it makes me cry. I get really worried about my career, and my classes. I constantly worry about whether or not people I am friendly with like me, or if they’re just being polite.

Wow, that’s suddenly a really long paragraph, and I could write so much more about all the things I get anxious about. But I won’t right now.