Without vulnerability there is no intimancy?

It's true, at least that's what I've learned since being married, and it's not something that just happens once and that's it. You can't just say o.k. I'm going to allow myself to be vulnerable in order to become closer and therefore more intimate w/ this person and that's it. It has to happen over and over in many different situations and for me it's been really hard because I struggle a lot w/ trust and it's hard for me to become vulnerable even after 7 yrs of marriage, and even w/ a husband who has never given me a reason not to trust him, I just have issues that I still carry from my childhood.