Make some structure for yourself and work on sticking to it, or at least getting back to it when you fall off the wagon.
I have a lot of symptoms of ADD-- my solution for difficulties is either creating a structure (that I can't seem to stick with) or dropping things entirely so I can have a chance at focussing on fewer things. I have to work to keep myself on task, but I have learned enough discipline to not take on too many projects. Too much externalized structure stresses me out. I feel better when I have time to let my mind and body wander freely for a while. Not enough structure stresses me out, especially in regards to work and money. I can feel busy and purposeful when I have a focussed job to do... until it is suddenly too much for me. When I get stressed, I need stillness and quiet to calm the mental storm. I need escape from others' expectations, especially. I'm a nervy, contrary person in general, I guess! It's crazy and the need to adjust the balance is constant.
I set myself the task of creating habits for myself that make be a better unschooling parent, instead of focussing so much on creating habits in the kids. These include record keeping, cultivating energy out of parental torpor 
, acting spontaneously (pulling over and stopping instead of driving by something interesting, taking a different road by request), soliciting input to plan days (still working on that one), getting the basic chores done to clear a chunk of my day to be available to them (definitely still working on that one!) And whatever else.
Here's how I keep myself busy and modestly structured:
First, my week is laid out according to our activities: gym on Tuesdays, Girl Scouts Wednesdays. Riding lesson every other week. I work one day every other week. We are going to try fitting in morning open swim with my short day and have them work with me, since it's a long drive and the Y is on the way. 4-H is monthly. OK, anyway..... that is the basic structure.
Mondays I try to get a new "homeschool calendar" on the fridge. I miss weeks, for sure. I write down everything remotely schoolish on this calendar. Now that my oldest is declared, it will be the basis for our record keeping. I give them their allowance. We plan our next day out, unless it is riding day. This is the day I am most likely to renew our vast borrowings from the library online and order new books and videos. (I keep a "library list" next to the calendar for requests. I also use this to write down ideas).
I do miss weeks, like right now. But I've been doing this long enough that I go to write something on the calendar---and it's not there! Crud. All I need to do is fold a sheet of paper in 8 sections, use a sharpie to draw lines and dates around the sections, and voila! Calendar! A heavy duty hole punch and a bevy of binders from the thrift store are nice, too, to store old calendar sheets. I have a binder for ideas, one is something of a calendar of events. I like to scroll the local library event offerings, see what is offered in our community. It is a bit random. Right now my assignment is to find an Irish dancer performance because dd2 loves watching and we are missing the next free one (we are visiting a chicken breeder's show near Seattle).
I like to start my mornings slowly while the girls watch videos. Sometimes they go play, but I don't like diving into needs and chores first thing. They don't have a clear-cut structure, but they do have a loose rhythm. I have my own rhythm, a bit different from theirs.
Prepare yourself for a little bit of randomness in regards to your son's learning. Meaning simply that it is probably not going to follow any set learning plan, or be in a particular order, or achieve competency before charging on to the next thing. If you can let go of the fact that it is not going to unfold neatly, if you can busy yourself documenting the unfolding instead of judging it, then you will feel more confident.
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