I don't really know much about body dysmorphic disorder, so I can't say anything about that.
But I can say I REALLY understand where you're coming from and relate a lot. My acne makes me feel so unattractive, it's caused by a medical condition that causes me to have a hormonal imbalance. But anyway, some of what you said, I've said too. I can't process people finding me attractive. I don't get it. I wouldn't know why anyone would find me attractive. I'm told people flirt with me, but I have it in my head no one would ever want to, so I don't even notice.
I'm just sharing so you know you're not alone. I really hope this gets better for you. Stay strong. It sounds like life is rough and overwhelming, just take it a day at a time and look into stress management.