Some of my lists are in the form of one item per sheet of paper. Sometimes it's just two words written in the middle of a letter-sized sheet. After I do it, I can erase the pencil marks and re-use the paper. Advantages: it's less intimidating because I'm only looking at one item at a time and fully focussing on it, rather than reading a list with several difficult items at once. Also, I can very easily sort the items by moving the pages around into different folders. Typically, I take the top item on the pile and deal with it in some appropriate way before moving on to the next. The way to deal with it might be just to move it to a different pile or decide to erase it because I'm not going to do it.
Your lists should serve you: the real you who has feelings and aversion to looking at lists etc., not just the ideal you. Years ago, before GTD, I made a great leap forward when I started giving myself permission to put X next to items in my lists, meaning I'd decided not to do them. When everything on a list had either a check-mark or an X, I would consider the list "done". Otherwise, the very items you don't want to do are the same ones you keep reading and re-reading because the ones you wanted to do have been checked off and removed. When you do look at your lists, you could mark some actions with "X" (or erase them) and mark others with "S" for "someday/maybe" meaning that on the next weekly review you'll likely want to move them to "someday/maybe", and then you can just look at the remaining unmarked items.
David Allen says that priorities are always changing. It sounds as if that's very true for you (though not so much for me). When you do things that are not on your lists, you're managing to take those changing priorities into account somehow. If your lists are to be any use, you need to get them to reflect changing priorities too. One way might be to think of the list as simply reminders of possibilities, not lists of things you should do; so that when a new thing comes up, you can just quickly scan your list and think "yup, as I thought: there's nothing here more important than this new thing" so you can feel free to do the new thing without worrying, or else you can decide to reject the new thing because there is something more important on your list (Hmph.) unless it's feasible to schedule both. Another way might be to keep changing your lists, for example the way I shift sheets of paper into different folders.
One thing that really helps me is pre-sorting my lists by priority and by energy required. Each context list is a page, and on that page I write things that will take more time and energy towards the top, and things that are more important further to the left. If I'm tired or if I only have a few minutes available, I don't even look at the top; I just start at the lower left, and I'm not reading anything that's too tiring to even think of doing right then. Usually I start at the upper left. That way, I usually don't have to read the whole list. I only read a few actions, and assume that all the other actions which are further to the right are of lower priority so there's no need to consider them right now.
When a new thing comes up, rather than just immediately doing it, you can write it onto your list and then do it. This might help you gain a sense of perspective as to how its priority compares with the other things.
You might want to post a few examples of your next actions, so that people can comment on whether they're expressed in a sufficiently doable way (or maybe you'd prefer to keep them private). E.g. "contact Sally about X" isn't GTD, but "phone Sally about X" or "email Sally about X" can be. Do you really know how to do each of the actions, or would you have to do a second or two of thinking first? Do that bit of thinking ahead of time. It really helps!
Sometimes I select a few actions and make a short list of the next few things I've decided to do (maybe about 3 actions). I'm just more comfortable sometimes knowing what I'm about to do. You might try that. Similarly, you might try reading over your list, once a day or whatever, at a time when you're not about to do something right then, in the spirit of thinking over what you might do a couple of hours from now or tomorrow or something. That may be less intimidating.
Or, you could decide that you're going to look at your list, select one action, do it, and then go back to your usual MO.
I don't think it makes sense to read over hundreds of actions every time you want to choose what to do next. You can pre-sort in various ways. When you design your list, think of treating yourself like a valued customer or something, and design a list that you'll find useful and enjoy looking at. What would a nice attractive list look like to you? How many actions would it have? How doable would they be? How long would each one take? Would there be things on there just for fun, or would there just be things providing satisfaction of a job well done? How many of the more difficult tasks would be included? Think about that and then try to design the list to serve the you who will be reading it (not the you that wishes all that difficult stuff could magically get done).
You can only do one action at a time, so presenting yourself with a list of hundreds of actions won't get any more done than presenting yourself with a manageable list of 5 actions. If you do get them all done you can always choose more out of someday/maybe. (At least, I've heard that in theory you can, though I'm not sure that's ever happened to me!)
. It is just no fun looking at hundreds and hundreds of tasks and projects.
