Please help me

I always feel so depressed and so anxious whenever my boyfriend goes anywhere and i get really shaky. I overthink on situations hugely to the point where it’s affecting my mental health. He has never done anything wrong he is very open and never secretive he is an amazing guy. But I have this problem when I freak out anytime he is near a girl and I know it’s all trust and I do 100% trust him but there is something wrong. He curves every girl and tells me immediately if a girl has tried to do something or said something. I get really badly depressed and I don’t know what to do. Please help me