Can't help but to worry about not topping my husband's relationship with his ex.

My husband and his ex were together for almost 6 years, since high school. He's 24 now and they broke up when he was 22. He met me shortly after and proposed after only 4 months. He has a child with his ex so he still sees her at drop offs. I can't help but to compare myself to their relationship and I always want to make sure I'm better than her. He always talks about how she never bought him anything or cooked or did anything for him so I always make sure to do those things for him. She always accused him of cheating and stuff and argued with him but he put in so much effort for her. If we argue, I'm always the one to fix things when he used to with her. He says she messed him up. Is it normal to feel like this? I always want to be better than what they had. They were together so long and did so much together and knew each other so well. We've only been together a year. He says he married me so quick because I'm everything he tried to change her into being.