Girlfriends guy friend

New to this community and sharing about my feelings in general so please bare with me if anything doesn’t seem clear. Basically what’s been going on is for the past few days my girlfriend of 1 year has been hanging out with her guy friend everyday. I have been feeling insecure and jealous about him because deep down I just have this feeling that they’ll develop feelings for each other and she’ll just lose all interest in me. I tried communicating with her about my feelings for a few days but I was speaking from a place of fear and insecurity so we didn’t get a chance to really have healthy communication. I suggested we go on a break so that I can work on my own self worth and self confidence and also just focus on my mental health as a whole. I genuinely just haven’t been sleeping well I haven’t ate anything. I get these random thoughts of her and her friend having so much fun and I just feel inadequate. And don’t get me wrong I know my girlfriend doesn’t have that many friends to hangout with besides me and this is healthy for her. But I just get so hurt seeing them together. I have trust issues from past relationships that I’ve been trying to work on for my girlfriend but this just seems like a big leap for me and I just don’t know how to handle it.