I had so many moments just like that throughout my 5 years at school.

Here were my solutions to the loneliness.

Join a fraternity. You will only like being around a handful of the guys but that's a handful of friends you didn't have before. It will force you to get out and will also force you to make sure your grades stay up.

Find hobbies. My 4th and 5th years were consumed with video games, playing guitar and recording music. If I wasn't working on school then I was doing that.

Get in a system. For example. Saturdays I would wake up. Go straight to the coffee shop and spend an hour studying/working. Grab some donuts as a reward and head home to chill out the rest of the day. Sunday I'd do something similar. Week days, I made sure to have everything done before i left campus. That way I never had to worry about stuff when i got home.

College sucks for a lot people. I was one of those people. I had fun and made friends but the overwhelming majority of my time was spent stressed out or depressed. You just need to remember you have the most free time you'll ever have while in college. Take advantage of that. Also recognize that you get a much better start in life with a degree. So while this sucks it's just paying your dues for when you can get a job.

Think of that first job out of school where you'll be making 30k minimum. Do you even know what you'd do with 2.5k a month? It's worth it. It sucks I know. Just gotta push through. By your last year You'll be happy.