Hm. I dated a girl like this. In emails and on the phone she’d blab away about all sorts of crap. On dates, she’d clam up.
Basically she was afraid of what people thought of her. She was afraid of making a bad impression or doing something wrong. She had no self-confidence and she tended to put herself down.
The problem is she was giving in to her anxiety. Her anxiety prevented her from developing confidence because she never risked being herself around guys.
So your issue is you are too anxious to say stuff. That’s because you are focusing on the BIG THINGS like how you “feel”. Stop worrying about the big stuff. Build yourself up bit by bit. The more you focus on the big stuff the more overwhelmed you will be.
So get to know a guy. Focus on the things about him that you really like. THe more you focus on someone else, the more relaxed you are (I absolutely hate how insecure girls are SO focused on their own worries they never even ask about me or what I think or what I’m doing when we’re dating… they are like black holes, smiling and nervous… yuck).
The more you focus on him and doing stuff with him, the more you can talk about what he does, things he says, things you do together. This allows you to see how compatible you are as you talk about issues based on real life stuff you are seeing and doing. Your feelings become clear based on these discussions (ie. you admire him, enjoy his sense of humour or creativity or assertiveness or whatever). He will see it.
You can get into all the words stuff wayyyyy down the line when you are both so comfortable and sure of your compatibility that there is no risk anymore.