Stupid anxiety

So I know this sounds stupid but I get really bad anxiety whenever I have to go somewhere without my family (mainly my mom). This week I’m going to be somewhere without them (except my older brother) and it’s really freaking me out. I feel like maybe saying something here will make it better, but I don’t know what else to do to make it not happen. Normally when I have my anxiety attacks I just start crying and can’t stop. I really don’t want that to happen because I’m going to be with a bunch of other people. If anyone had any ideas on how to help that would be great!