Hello EmilyK: I noticed this is your first post here on PC. So... welcome to PsychCentral.

Of course we here on PC can't diagnose you. This is a job for a mental health professional. You might start by talking with a school counselor if you're still in school. You could also, perhaps, seek a referral to a mental health professional from your general practice doctor. Or you could see if you could arrange to see a mental health therapist in your area. Seeing a mental health professional is the way to figure out what is going on with you.

In the meantime, one additional thing you could do would be to take some of the quizzes & tests that are on offer here on PC. Here's a link to the listing of quizzes & tests that are available:

Psychological Quizzes and Tests

I know you mentioned you don't think what is going on with you could be MPD. However reading through some of the posts in the dissociative disorders forum, as well as perhaps posting there yourself with regard to what you are experiencing, may help you to clarify what's occurring. Here's a link to that forum, just in case you haven't already found it:

https://forums.psychcentral.com/dissociative-disorders/

Here's a link to an article, from PsychCentral's archives, that offers an in-depth look at dissociative disorders:

In-Depth: Understanding Dissociative Disorders

And lastly... you might also want to consider introducing yourself to the general membership, here on PC, over on the new members introductions forum:

https://forums.psychcentral.com/new-...introductions/

I hope you find PC to be of benefit.