How to show vulnerability to a guy

So me and this guy have been on and off talking since we were 13. We’re 18 now. Ive always loved him and he’s always admitted his feelings for me but I’ve never felt ready to open up about how I feel.

I think I’m finally ready to. Any tips on being more confident?

The only reason I’m scared is because I never talk about my feelings, I hate showing my vulnerability. But I feel comfortable around him and want him.

Everyone has always said how we’d end up back together and I can see it happening but I don’t want my insecurities (mainly about my body) to get in the way. Please help!!