I was feeling similarly prior to my last session. I spent time trying to get it down to a list and came up with two pages of writing. I had shared my concerns with the T prior via email. It was a weird start to a session because I still didn't know where to start. We ended up just jumping into the middle of things until we found the current that we needed to follow. If you can call before or email, it might help. The list idea and writing for a bit also helps to narrow it down and get you more focused on what you want to say and what is having the biggest impact on you and in finding themes. You may still feel nebulous, but it will be a more condensed nebulosity, I guess. I noticed that all my stuff was relationship oriented so it gave some form to the session.