How to help improve her self esteem? Me and her both 18YO

Long story short, we both like each other and people like her ex has scarred herself in a way that makes her feel like she's not worth it. I'm proving her otherwise and it works, temporarily as I have to comfort her again after a while. I honestly love doing that, but I heard its bad to always be her confidence booster? I feel bad because I really want to help her...How else can I show her amazing worth?