I know how you feel. I used to have some very bad days/weeks/months after google update back when i was doing client SEO.

I found the main issue is not google, but the clients. Especially the ones who are at the edge of their seats all the time thinking their life will end if site page drops off page one. And the ones who don't understand that ranking takes time, and give you hell and brimstone because they are paying you NOW and aren't seeing any results NOW. Or they aren't actually tracking their ROI's and figure you're not doing that much for them, terminate agreements and walk off with all the hard work you've done for them over the years => Bye bye time, business and everything you've invested into their site.

I stopped doing SEO and started renting out domains, and generally working on performance based rates. My life is a LOT simpler now. Google updates don't bother me that much, and i get around to it when i get around to it. No more angry calls, no more pesky clients, no more threats of contract terminations, everyone is happy, especially me. Best part of all this; if i do get an annoying client, I just cut them loose, and i loose absolutely nothing because the domains all belong to me, and i just transfer them to another, less demanding client.

Downside is I do have to perform to get paid BUT, I was doing that anyway, and now it's on my terms and i know that the investments i make and the work I put in all goes into my own assets and not someone else's.

Also I've found that google will be a much better friend to you if you provide them with the content they want people to find. So instead of building domains tailored to the client i just find clients tailored to the domains now. Makes it much easier to avoid google slaps, since they're basically on the same page.