How to break up with someone without seeming shallow?

I've been with my girlfriend for 3 years. I love her personality and I used to think she was pretty. She exercises so she's in shape so weight isn't an issue. My problem is something she can't change. She has keloid and hypertrophic scars. She got a belly piercing ( she didn't know she had keloid scarring type of skin) and they become keloid. It literally looks like she has two pea sized scars as a navel piercing. It's gross and she's self conscious about it. Then she got bit by mosquitoes on her shoulders and those become nasty scars also. It's just gross and I can't show her off anymore. She used to wear cute crop tops and now she doesn't anymore because her stomach is ugly now. I don't even want to have children with her anymore because IF she might need a c section I'm sure the scar would turn into a keloid. Also, her future pregnancy bumps will not be cute because of the scars. A relationship has to have physical attraction also and I can't seem to love her body anymore. If I would have known her skin was like this, we would never be together. How do I break up with her gently and not make her more depressed?

The picture isn't my girlfriend. This is just an example of a keloid scar. They can be small or huge. Also, they are very difficult to treat and will always most likely come back.