I struggle constantly with the fear of being too needy, in fact, that was one of the topics my T and I were working on this morning. So, I'd like to share a few of my experiences with you in this regard, perhaps it will help.
My T went on a retreat this last week, so I haven't seen him for about a week and a half. I also did not e-mail him, because I was trying to be more independent and trying to respect that he was on a retreat and give him space.
Well, over the week, I've been getting more and more angry at him. In part because I wanted him to just check in with me at some point while he was away. I didn't ask him to do this, so it wasn't logical to expect him to. When I told him what I was mad about, he told me that he should have checked in with me and asked me to forgive him. Which was about the last thing I expected to hear. I had a hard time forgiving him because I couldn't see anything he did wrong. (I was also crying so hard I couldn't speak) I felt like it was my neediness that was "wrong." He insisted otherwise.
He assures me (repeatedly) that he will contain things if he needs to, to preserve our relationship, and that I need to trust him to do that. I don't need to be terrified of loosing him because I'm needy, because he won't let that happen.
To shift gears a little, regarding wanting contact and not knowing what to say. I've had a few times when I could really have used some support from him but had no words for it, like you describe. I've talked to him about this, his suggestion was to call him and tell him exactly that; "hello, I don't know what to say but I feel like I need to talk to you."
I hope this brings you a little comfort