Jealous & Insecure...Please help me😔💭

I've always been so insecure but now I'm realizing that's what's causing my jealousy. My current relationship, he's never really given me reason to feel jealous or anything but I just can't help it & I HATE it. It's ruining me emotionally & ruining our relationship. How can I stop this? What have you guys done? Any stories of yours? And it's not like I'm this ugly girl. Yeah I have my flaws but to others I'll ACT confident but when I'm home alone, all these thoughts run thru my head of how can I be prettier, how can I make myself curvier, how can I get rid of all my scars. I know I should be happy with myself but for some reason I find it hard...idk why....God forbid I see my boyfriend looking in a pretty girls direction, I wanna lose it. I think he thinks she is prettier especially white girls with blonde hair because he's always said he wanted a white girl even when me and him were friends. I hold onto everything & I just wanna let it all go. I wanna be comfortable enough where I don't feel so insecure with him around girls, comfortable enough to not compare myself to other, comfortable enough to know what I can really be worth. This is honestly pushing me to a point in my life where I don't even wanna be around no more cus it adds to the stress I already have....I'm about so close to losing it😔