what should i wear for a date with my boyfriend?

we been together for 3 years almost 4.. I feel like he doesn’t find me attractive anymore, He never says i’m beautiful and all this nice stuff.. I feel like i gained weight and not his type anymore,, we are going for dinner and a movie so i wanna dress to impress, not slutty either just something simple but yet He will be not embarrassed of me and staring at me.. I want to feel beautiful. 😰