FOMO (Fear of missing out)

Why do I have fomo and have social anxiety at the same time? I am scared of not being included or invited to things but I also feel this incredible anxiety when I am invited. How can I deal with this? I’m doing a master in an other country. I know what I want and I have a life organized. I wanted to study this but the part of marking friends and going out takes me back to does days in high school when I felt like I needed to feed in and be liked and be part of everything. I hate feeling like this because being here is an amazing opportunity and I feel beyond lucky but I am scared that I feel like this just being a month in and still have a year to go. I feel like my safe place is my family and my boyfriend and I feel outside here.