Scared of being excluded

(Original post by Anonymous)
At university I’m living in a flat with a couple of people who are all really nice and easy to get along with. But I have really bad anxiety and I’m very shy, sometimes it’s fine and I can leave my room and talk to them for a bit with always makes me feel pretty happy and proud of myself for a bit. But there are so many times where I’m just sat in my room and I can hear lots of people outside laughing and talking loudly... This always triggers my anxiety and fear of exclusion, I just feel like I’m missing out and more than anything I just want to go out there and join them. But my social anxiety keeps holding me back so I’m usually stuck in this annoying mindset where I’m desperate to socialize so not to be excluded but I’m also terrified to socialize because I’m so shy. But hearing them all laughing out there makes me feel like they’ve all bonded and built a friendship that I’m missing out on... I hate not knowing what I’m missing out on by hiding away in my room, all the flat jokes and stuff. When I do leave my room I talk to them and it’s all kinda polite because I’m so quiet... I just hate it, I’d love to hang out with them more because they’re all seem so lovely and I know they wouldn’t judge me but for some reason I can never force myself to leave my room when I hear lots of people talking out there... If it’s just like one person it’s fine, but just walking in on a conversation that’s already begun makes me feel like I’m not welcome or something. I can’t join conversations it my worst problem...