I've had this same problem, specifically with regard to the pace of communication now that all communication is instant. So I created an email platform that sends and receives messages once a day: https://www.pony.gg/. I am in the process of launching it now. Would greatly appreciate feedback.
More broadly, I've read about this issue a few times here on HN as well:
https://ubiquity.acm.org/article.cfm?id=1455706
and a few other links I'm not.
EDIT: found working link
The perception of time depends highly of what you are doing.
You could separate easily semester because you probably took totally different courses so they were easy to distinguish, now that you have settled and that you are doing mostly the same things every semester, all is blurred. This is totally normal and how the brain works.
One solution would be to change job every semester, but it might not be the ideal solution for other reasons.