Will my girlfriend break up with me!?

I have pectus excavatum (chest wall deformity) on one side of my chest. So my chest is uneven as my left side is normal and my right side sinks in a bit. It is too mild to get surgery on (i talked to a surgeon) but it is still noticeable. I have been with my girlfriend who is 16 and i am 18 for 3 months. She has no idea that I have this condition. I like her more than I explain and i worry about telling her I have this because I don't want the good times to end with her. I am in love with her and I haven't told her that. I know she likes me a ton, but I feel like if i showed her my chest she would think less of me or be embarrassed of me. I have contemplated suicide because of this condition because I can never see myself as being considered normal. Please help me. Is she going to break up with me? My gut feeling says she won't break up with me, but I don't want her to think less of me! gahhh.