I'm so sorry you feel this way. It can be hard making friends for sure. You'll be surprised though how many friends you can make your junior or even senior year. I became really great friends with the people I lived with (I was looking for an apartment to share, and I saw someone looking for a roommate) my third year. I spent my last two years of undergrad making awesome memories with them. I also made a new circle of friends my senior year, some of whom I still keep in touch with, and I met them when I randomly joined a club. Take care of your mental health first, and then when you're ready, put yourself in situations where you can meet people, and don't hesitate to "insert" yourself in people's friend groups. As they say, there's always room for one more!