Hi Sadbarista,
Welcome to PC! I really relate to what you say that it feels like life is moving on for other people but feels unreal to you.

I live with depression and that often makes the world feel unreal, like I'm watching myself doing things and other people living in it.
Anxiety can also make one feel detached, like in a bubble.

Sadly some things have to be done a t a particular stage in life like school, college etc and then we just have to do what we can, whatever it feels like. That's hard, but it can be possible, with the right support.

What support is there where you're studying? Is there a counsellor you can speak to who can help you through and help you with the questions of who to tell and how?
Some people it is helpful to tell and they will be supportive, others may be dismissive or unhelpful and you are probably the best person to decide which is which.

My feeling is that you need support from someone, and possibly professional support. A counsellor or trusted teacher/lecturer may be best placed to help you decide.

Don't try to live this by yourself.

Whatever you decide, I wish you well and hope to hear more from you.
We're here for each other.