Your comments on your writing slump made me think of a few things. I don't know if they'll be helpful or not, but they're things I consider whenever I feel like I’m in a slump.
I commonly go through periodic writing doldrums, although the good thing for me is that I've been at this long enough that I always have something unfinished I can turn to when new writing feels impossible. I also think (and please don't take this wrong, because I'm the old old person here and always will be, compared to you) that it comes from being a little older and a little farther along in your own development as a writer. It does get difficult to maintain enthusiasm at times, especially as life becomes, if not more complicated, more requiring of a consistent daily effort to maintain jobs, love relationships, families, friendships, social or political commitments and so on. I think there's a lot of thrill that comes from those first few years of writing and publishing success: "I can really do this, I 'm really good at this, other people think so too," and all that goes along with that feeling. But then, for the first time, you get to a point where you have to do it all again. You're always starting over but it doesn't feel like a start because it feels like you've started before, and how is it fair to always have to be starting again? A great Elvis Costello line: "I had 20 years to make my first album and six months to make the second." From your letter it almost sounds like that's where you are, at the start of the second (major) push. I know we have many phases and many pushes, but it's probably true that you've never been at the point where you've been a successful writer before (chapbooks, the collaborative book, so on) and now have to try to be a successful writer again. Congratulations: you've reached that great moment when you have a public writing history and it has the chance to burden you.
If you're at all like me in this regard, adrenalin is important when it’s time to write. Feeling and trusting the energy is important. But how to get to that energy when it seems like other things are taking it away? I don't even have a good answer for myself, but asking yourself that might come next. It's weird what things will work for me: somebody gives me a writing assignment, or I pick up a wave of energy from something I haven't finished, and that speeds me into something new. Those are the good ways. Sometimes I’ll get a surge of energy from internet annoyance that’ll pick up my pace. Anything to avoid the leadenness, the feeling that I just don’t give a damn about my writing or anybody else’s. It may be that some writers can work within that leadenness, but I can’t, at least not often or well. I need to believe that I care about what I’m saying and might say, and it can be hard to convince myself of that.
My guess is that it’s not so much about revising your current manuscript, although I know you have some issues about it that feel unresolved, but how to take the next steps in becoming the writer that you already are. Your life is probably different than it was, your concerns are different, and that means that the likelihood is that your tone as a writer is going through changes too. So it sounds like maybe you might want to think about new ways to give yourself the energy you need. I don’t have a suggestion for that, except to ask when you might find half an hour, or an hour, in a day, maybe only a couple of times a week, and find ways to create energy for yourself. Who knows what it takes? I wrote almost all the Felonies of Illusion poems while reading Clark Coolidge’s book The Rova Improvisations and watching re-runs of the sitcom Friends simultaneously. Or not quite simultaneously. I’d read a poem on the commercials and write my poem when the show came back on. I could bounce off the language differences between the two in a way that made it possible for me to write words down on a piece of paper. So any weird habit will do (and mine are very weird) if it gets you where you’re trying to go.
I hope this doesn’t sound too much like advice. It’s not so much that as yeah, I think I know what you’re feeling and here’s how I’ve tried to think about it. For what it’s worth, I’m pretty sure that you’ll be writing again soon enough. Easy for someone else to say though, huh? The writer herself or himself is the one who has to get geared up again to go.
Any thoughts on how to get past the writing doldrums, yours or anybody else"s? I'd love to hear about that or anything else having to do with the issue.