Confidence?

What do you guys do to gain confidence? My boyfriend always compliments me & tells me how I’m perfect & he loves me but last night he said that a girls photo on Snapchat made him “speechless” & then he goes, “your photos make me speechless, too!” But the thing is, this girl is the COMPLETE opposite of me. She has a very tiny waist with awesome curves & has blonde straight hair, while I’m heavy with some curves (because of my weight) with very curly brown hair. It’s been bugging me ever since & we talked about it & he apologized but every time I look in the mirror all I can think about is his voice in my head saying that her photo made him speechless. It’s killing me. I do all I can to dress up for him (when most the time he doesn’t even care & wears shorts & tshirts) & I always try to do my hair & put on makeup & everything I can so I can be pretty for him & I thought I was doing so good but last night just killed me. Just absolutely killed me. What should I do to boost my confidence? Also, do you think I’m overreacting?