It's a shame your husband does not have a positive and supportive workplace as it seems he is easily intimidated under duress. While being self employed can be one solution, the added pressures of management can be overwhelming making it a case of 'out of the frying pan and into the fire' for the unwary.
Glad to hear the kids are not the brunt of frustrations as much, but I can't help think that this behaviour is 'mid life crisis' - wanting to chuck it all and have some fun.
Perhaps some CBT from a psychologist could turn things around for work/life balance, or even some marriage counselling could help address the harm being caused to your family and help find direction again.
While simply finding another job may only defer the same response, it may be useful to capitalise on his interests to start a whole new career - ie, a keen golfer could consider coaching, open a supplies store, or just become a greens keeper. The right choice can actually be an engaging form of retirement.
The house construction process is a job in itself - has this stalled to further drag the mood down? Small consolation, the weather is improving but it is really hard functioning during renovations at the best of times.
Telling you what to do is beyond my scope, but I hope these suggestions are of some value and can help lead you to a workable solution.