Liveinthepresent,
I also think with Celexa that a regular ECG/EKG is usually done to monitor your heart rate. I think that is only done for high doses though. [They did that for my son too on another medication called Orap. They took a baseline one before starting the med and then he was to have regular ones after that. Didn't end up needing it though as he couldn't tolerate the med.. ]

Don't worry about being different from your classmates too much though.

If you're generally a calm and quiet person, there's absolutely nothing wrong with being like that! However, if you're feeling flat, fatigued and finding no joy in anything and just generally blah... worry about that.

My son, my daughter and I have social anxiety issues. It's no fun when you're having to deal with crowds and classes etc.. If you have diagnosed condition/s then you can get accommodations at college/uni for certain types of assessments such as having to stand in front of a class and talk for 10 minutes etc.. My daughter's battled with that terribly lately. The doctors prescribed her some Propranolol on an 'as needed' basis, but it doesn't help so much.

Anyway, sorry to ramble.
You take care of yourself.