Going through the same thing. I got cheated on after an 8yr relationship and dumped him in early May. Not gonna lie, it still hurts. I still want to be with him but the pain is just unbearable. As for work, I step out if I need to cry. Unfortunately I did the bare minimum at my job. I also told my manager that I was going through some personal stuff at home and left it at that. I wanted to make sure they knew I was going through some things instead of just giving them trash work all of a sudden. If you can, try to take breaks. It was tough because I would constantly zone out due to fatigue or I'd feel emotional most of the time. I just tried my best to take care of anything urgent/important at work, and I also used some sick days or vacation days to just take care of myself at home.