I'm trying not to be mad at him

My boyfriend missed our date yesterday. He has this girl he's been friends with for a long time and before he came to get me for our date he had stopped by her house to check on his dog. She has his dog because he's still waiting for his therapist to write him a note stating his dog is an emotional support dog so he can have her in his apartment. So he checked up on his dog and dropped off some food. His friend was in the kitchen and I guess she was standing on the counter trying to reach something because she's super short. She ended up falling and hitting her face/mouth on the counter and there was blood everywhere so he ended up calling me saying he was taking her to the Hospital. As far as I know she's fine now. She did lose a couple teeth. He is taking me out today but I just still feel pissed about the whole situation. I'm very insecure, I will admit that, and I am very jealous of her and how pretty she is. Especially since I know he's into short girls and I'm on the taller side. I'm honestly still really mad about everything and I'm trying not to be mad because we have a date and I don't want to ruin it, but still....