I want to know how to tell if I'm ugly or not

I'm beyond distraught. I've always thought I was kinda ugly but I never really accepted it. 
Today, I was out at a concert and lots of pictures were taken. I just feel so horrible about myself.
 Just looking over the photos makes me want to cry. I'm at an all time low at the moment, like I get friends and family try to comfort you by saying you're pretty but I can just tell that I amnt.
 I'm just devastated that all my friends are gorgeous and I look like the hunchback of notredam. 
And I get when people say "looks don't matter" or "what's inside that counts" and even "just love yourself the way you are" but those quotes feel very shallow to me. 
I just don't know how to feel. 
Is there any way I can tell if I am actually pretty? I know I can't really trust opinions simply because people are never mean enough or honest enough to be 100% truthful.