I'm really feeling lonely lately

I'm a 20 yo guy, everyone around me seems to enjoy the simple pleasures of life, hanging out with friends, playing games, reading, etc. While I have enjoyed those things, I've felt really lonely lately, as of the past year. It's hard to explain, the more alone I am, the more alone and disconnected I feel. I'm physically alone probably 80% of the time, even during school. It's hard for me to explain, I just feel like I'm kinda disconnected from the world I guess. I don't really use social media, I don't talk to most of my friends. It's hard to break that barrier to get back to being connected. I just wanna feel like I'm connected to the world, like I'm not the only one experiencing life.