Hi! Welcome to GTD! I hope you like it. I find it really helps me.
I'm not an expert on GTD, just another participant in this forum; and I don't understand exactly what you've done or what stage you're at, so I'm not sure exactly how to answer your question, but I have some suggestions and some questions for you. You can decide whether my suggestions are useful for you.
-- You can re-read the GTD book, or at least the parts that refer to what you're doing now.
-- You can list all those "next actions" in "context" lists. For example, make a list of next actions to do when you're at home, at work, out shopping, on the computer, making phone calls etc. I suggest making sure each "next action", or at least one "next action" for each object or document, gets onto at least one list. When you do that action, you can then copy the next action for the same object or document onto one of your lists.
-- Then you can take the context list for the place where you are now, and start actually doing some of those next actions! First select the ones you have the time and energy to do right now, then sort those by priority and start on the highest-priority ones.
-- You can consider each of the "things" with next actions attached to it to be a "project" in GTD terminology. You can choose a place for project support material, and move each of the things off your desk and into that place after you've copied the next actions onto an appropriate list -- and hopefully end up with a lovely clear desk that you can spread one project at a time out on as you get around to doing them!
A "list" can be a pile of papers with one "next action" written on each page. I like to do it that way. There's lots of room on the page to write related thoughts or information if I feel like it; it helps me focus on one thing at a time; and I can easily erase my soft-lead-pencilled writing and re-use the page when I'm finished with it.