I realized this very helpful "tip" the other day. This may or may not help you.
So, for me it's not about thinking that I'm pretty or I'm ugly. Yes, it does make me feel better when I think I look good, however, this is very short-lived and the fallout is excruciating! So, the key here is not trying to see your physical image as pretty or handsome, but convincing yourself that it doesn't matter what you look like, so who really cares?
As long as I'm the best person I can be, I will be fine. Be smart, be thoughtful, be mindful, become beautiful <3