Struggling with social anxiety and masking, even with my closest friends

I hate how my social anxiety has gotten so bad that even when I'm just meeting up with my closest friends I still feel so uncomfortable. Since graduating I barely see my friends anymore, so I think that might have something to do with it. But they're still my friends and I just don't understand why I have such a hard time with just hanging out with them. Like, tonight I'm supposed to meet up with a few of my friends for the first time in months, because one of my friends who doesn't live in the same city anymore is visiting for a few days. I miss my friends and I genuinely do want to see them, but even just the thought of it is making me SO ANXIOUS. I haven't been able to do almost anything today because I've been stressing about it so much. I've also noticed that since we don't see each other nearly as much anymore I feel like every time I do see them I have to mask like crazy, and it's SO EXHAUSTING! I just hate how I can't just be in the moment and enjoy seeing my friends, because I'm just so overwhelmed and anxious and masking. Why can't I just be myself around them anymore?? It honestly makes me feel so lonely at times, because even when I'm with them I just feel alone.