What are methods to help me with this?

In the last couple of years I've made some good progress becoming good at talking to women. I feel better talking to women and approaching them...I don't give a fuck...I get numbers find and I'm able to to go on dates and be totally cool..but I still have a huge hurdle ahead of me..it's being open and vulnerable emotionally..being close physically to someone...touching intimately..looking into someone's eyes while being 7 inches far from each other...breathing the same air..

As an anecdote, recently I watched 500 days of summer. They get very close and look into each others eyes, whisper, have sex, etc... it hit me.

I realized I've never felt love, got close to a woman's, looked in her eyes, or even kissed one..I'm not sure how to do any of these things...I don't know what to do in terms of what i'm supposed to say or act....i'm not socially awkward. I'm great in groups and in casual convos and i've always been comfortable around people in casual situations..but I've never been intimate or physically close to another person.

right now it's one of the only things holding me back from getting very close to women. i've become comfortable with all the other stuff..but this is as far as I go and i stop when it gets anything close to physical. another reason for my slight qualms about this is i've never kissed a girl or had sex and i'm in my 20s and it'd embarrassing for me not to know something like this. i'm just completely unsure how the girl would react. i dislike feeling "weak" and not being able to lead the interaction. feels a bit emasculating.

I want to solve this, what are some solutions and things I should try?

tl;dr how do i become more comfortable with physical and emotional intimacy, being extremely close to another person and in an intimate 1 on 1 setting.