I was exactly like that in 1st year 2020, it was so bad. I was the last to move in so everyone had already gotten close with each other and I felt like a total outcast, having anxiety made it so much worse too. I could barely start convo with anyone and whenever they did drinking games downstairs, I would literally stay in my room. I'd even cook dinners and put it containers at like 6am just so I didn't have to see anyone in the kitchen during the day loool. Have you tried medication for your anxiety, or spoken to your doctor to take therapy? But honestly, just try to initiate convo with them, try be yourself and they'll feel more comfortable to be your friend. If not, maybe transfer to a studio room and go to societies? what about the people on your course, do you speak to them? My anxiety couldn't deal with living with 11 other people I went home after a month LOL.