pretty much been said here but..

1) Step sloowly.. It's easy to lose perspective here and make decisions you might regret later..

Case in point - worked at a company that was acquired for lots of $$$ - while the founder did well, his 'explanation to the company for selling' email basically sounded like someone whining about not being able to handle stress when essentially he was running the place 24x7 and could have easily structured himself at arms length.. and it was not a small shop at that point either with several 100s of employees.. I'm sure with proper perspective he could have done much much better (like, orders of magnitude, potential internet mogul, etc) in the aquisition.. Those who are buying are not your friends, and are looking for anything to maximise their side of the deal.. taking advantage of your stress level and 'need' for escape will be one of them, and this only serves to let the team down in the bigger sense.

2) This is your challenge now. The company is up, it's running, it's doing well. The challenge now is adapting. Apparently you're having some difficulty with that. Others have mentioned vacation and refactoring your role and therapy or finding better life stress skills. I think that is your plan.

If I were you:

a) mini vacation: a couple days (e.g. long weekend) as unplugged as possible, possibly with trusted advisors or so, to think of any/all things that could be restructured to relieve immediate short term stresses in the course of 1-2 weeks, as well as personal planning for 'c' If advisors present, present it as 'getting ready for the next stage' (if you do still end up leaving, this will only help the transition anyway). include in this some kind of expectation for
a longer trip coming up, and how to manage during this time (others have mentioned this as a way for process inventory.. exactly)

b) implement the mini vacation plans during work in next 1-2 weeks.

c) do some quick hits in life structure while mini vacation plans are getting done: implement stress relief activites, reach out to a few ppl who can assist with venting/discussing in a constructive way. this would be the time for wife/friends/therapy/spiritual/healthy stress relieving hobby

d) Go on the longer trip. bring wife. rebond, get perspective, think of more in-depth ways to restructure your role going forward over the longer haul (e.g. 6mo-1y). Don't do this all day - make it a significant but not all encompassing part of your day. structure is key. also to see you are taking control of the situation - time managment here,getting perspective there, being 'in charge' yet not in the weeds, etc.

e) come back, implement longer term strategy. add further break at end of this, and revisit results. make another similar plan, resolve only to decide on the effect of the 1st 6mo plan after another period. (e.g. let your changes sink in).

not sure of your age/life experience but there could be other things afoot here.. e.g. you are dreading 'what's next' since life has been leading up to this moment and don't know what to do after, so better to 'take control' by quitting and then you don't have to deal.. the mind can play significant tricks.. so yes, hence #1 - redefining your role as accepting this challenge, and stepping carefully.