Sorry to hear your having a tough time, it does get better!
When we had Baja, he was kept in half of the kitchen with fences around keeping him in there, my OH works from home, so it sounds like a very similar situation. For the first few weeks I used to dread going home after work as it would be my turn to sit with him for an hour in his space whilst OH made dinner and Baja went crazy with me. Then he would eat whilst we ate, then sleep and then it would be time for me to give him another hour of playtime and try and keep him awake until midnight just so we could get 5 hours of sleep
I think being our first dog we were very cautious and unsure of what to expect, but within time you could trust him more and more and give him more freedom. Once he was out on walks things really changed and life got easier.
My OH does have an office upstairs, but moved downstairs to the kitchen table (in Baja's space) so he could spend time with him. As Colin has said they do just settle down and understand when they can and cant have your full attention.
Funny how Baja is almost 2 and a half and my OH is still working downstairs but moved to the comfort of the sofa
Nothing to do with Baja I must add, I think its Holly on This Morning that's keeping him down here
When we got Mole things couldn't have been more different, we were more relaxed and he only had a crate to go into, no big space just for him. We were laid back and started to realise that with Baja we just didnt get it and constantly thought he was going to chew up the house, in reality he's just not that kind of dog and at the end of the day these things can be fixed cant they!
Two things we couldn't have lived without was a routine that was stuck on the fridge which covered every hour of the day, which we made to work with OH's work pattern and a crate. That way when you need to have a meeting on the telephone you can plan your time to coincide with giving him some training/playing for 30 minutes before popping him in his crate to sleep.
As I've said things DO get easier, worry less and enjoy more. I wish someone had told me that when we had Baja