How do I make myself feel ok showing my face on facetime?

I just called with my idk what to call him, almost boyfriend idek and he really wanted me to show my face but I didn't want to, I really hate the way I look and eventually, after asking a few times he said: "whatever I'll call you later," and hung up. I keep apologizing to him but he just says whatever forget about it, I understand him 100% and I wish I could feel ok showing my face to him and its really not fair to him that I don't feel comfortable doing it. (I am NOT trash-talking him, I just need to vent, he is the most caring person in the entire universe, he talked to me for about 40 minutes about my insecurities and saying I'm pretty and he chooses me over all the other girls but I cant even work up the nerve to show him my face on call I am such a selfish bitch but I just cant. I'm so scared he's gonna leave when he sees what I look like even though he's told me looks don't matter and it wont change anything I just cannot get the thought out of my brain that he's going to leave me and now I feel like he'll leave me because I'm not showing him my face so I feel so trapped) I feel really really bad and I fucking hate myself but I'm not comfortable showing my face on the call. I've been waiting all week to call him and I've been so excited but now I feel like shit. I hate myself so much.