I think this is a common feeling GTDers get, even the black belts, at times. Here's what I do when my lists start to freak me out.

First, go through all my lists with one purpose: what are those next actions that have been lingering for a long time. It's amazing to me how I instantly recognize them: they stand out, screaming at me, it seems. I flag all of them (I use Omnifocus, but you should be able to flag them in some way no matter what is your tool). Then I tackle one at a time and make a big decision about each one.

1. I don't want to do it any more, and I'm fine dealing with the consequence of not doing it. So I delete it.

2. I need to do it, and I need to figure out why I am not doing it. I will create a project for it, if I cannot figure out what I'm stalled on it: "Figure out why I won't do ...." or something like that. The Next Action is, "think about it until I know what to do." That works for me.

3. I don't know if I need to do it. I am going to put it on a Someday/Maybe list to get it off of my attention for now.

4. Just do it, no matter how ugly and hairy it might be.

I have to do this quite often, actually. When my lists start getting long (I mean, any list is more than 20 actions long, if not sooner) I have to do this.

Chip