KP-
I also ruminate a lot and sometimes I just type it all down. I write my journal in my email account, so if I decide to read it to T, I can access it by phone.

Sometimes I have nothing to day and don't write. Sometimes I write too much. If I can't think of anything, I will just start writing something like:
I am blank at the moment and can't think of what to say. I have no idea what I'm going to speak about in therapy. I hate having nothing to say.

Then T and I talk about me having nothing to say and how it makes me feel. Writing nothing can be something to talk about, lol.

I wouldn't worry about the content of your thoughts, just put them down on paper whether they be happy, sad, dark, xrated, etc. Therapists usually say it's all gist for the mill.

When I laugh or smile . I want to mean it , does that make any sense ?
Yes, it sounds like you actually want to feel happy instead of just looking that way. But that is just how I see it, I could be wrong.

The best advice I can give is just write down what you are thinking/how you are feeling, and somehow, in therapy, it ends up helping, or at least it did me.

Good luck! Keep us posted. Take care.