Fear of losing everything

Over the past couple of months I'm scared of losing everything. Friends and family. I've been worrying and panicking way more than usual. When I worry, I sweat and get very warm with my heart feeling like it's going to explode out of my chest.
Over the past couple of months, I've felt like my friends care about me less and less. This feeling started in about September when I had to move to a new school for higher education meaning having to leave all my friends. I get these feeling like they always ignore me and they talk behind my back. Despite the fact they always reassure me they I am wanted by them, I feel they judge me and think I'm just doing it for attention. This feeling has escalated more and more and the fear of losing all of them is something I can't bare anymore.

Any tips of advice on how to control my worrying? Much appreciated