I think both of you guys need to give less of a sh*t about things, in a good way though!!!
I.e. if you get hit by a bus tomorrow and need 2 weeks off work to recover, the world will keep spinning, all of your projects will continue onwards, other people will find solutions and get things done. They won't be done right or perfectly, but they will happen.
You are not superman.
You are playing the role of 'hero' saving the day but you need to realise that is not beneficial for anyone long term.
Don't be a hero, don't work too hard. The company could fold or downturn or lay you off at any moment for no good reason. Just do a job to a decent standard and go home.
There is ALWAYS more that can be done. You can ALWAYS stay late and do more.
I did it myself for 20 years and got lots of promotions and money but really, looking back I should have held back a bit for my own sanity / relaxation / enjoyment rather than being the hero.
As MarkySimmo says above, he just does a job from 8-4 and stops.
My boss always says to me, if anyone is working later than 5PM, what the hell are they playing at, they should be delegating or getting resource or working more efficiently or SOMETHING to get the job done by 5, or just leave it til tomorrow.
Nobody outside of your tiny bubble cares. Before you were born and after you die, everything will still be there, chugging away.
I suffered from the same stress overnight, worrying what MIGHT go wrong and dealing with 1000 issues per day, but looking back, the company were using me and I was doing too much.