Insecure

Hey guys!!! So I’m not comfortable in my own body. I weigh 168 and I’m tired all the time I have no motivation to work out. The more I try the less I do I just end up defeating myself. I know it’s a mind trick n I’m losing! My fiancée says I’m sexy n not to worry so much. But I’ve known him for five years let’s just say I’m the only tiny dark brown spotted stumpy egg in a carton of perfect eggs. Should I believe him? I want to feel sexy! But when I work out I just feel so fat n it doesn’t help that I have bpd n I’m constantly torturing myself. What should I do? Does anyone have any thoughts on how I can keep motivated?