My self esteem is shit.

Sometimes I go onto my fiancés Instagram to look at his followers and the people he follows. Whenever I come across women they're always a million times more attractive than me and it ruins my self esteem. I can't help but compare my self to them and wish I looked like them or had their bodies. The sad part is I do it intentionally because I feel like he deserves better. I don't feel wanted by him as much as I did in the beginning. I feel like if I just lost the weight and had a nicer body he'd want me more. I feel like im being taken for granted but I don't blame him. I'm nothing special.