I graduated one year ago and I'm still not alright with it. It feels like I lost part of my identity (since I was a student for most of the life so far and no longer). Been unable to find a job I could be somewhat alright with and for the ones I wanted to do, I don't have either experience or correct school. So I fully understand how you feel.
However, I may be wrong but I feel from your post that you plan to stay here until "you retire" at least. Even after graduation and leaving the school, you can always learn new things and find purpose in something new. Whatever your path will be, I wish you good luck.