Hi, Those are the worst
For my 1st child I would pump often when I needed to leave a bottle. For my second I used formula when I left and pumped rarely, although still nursed for all his 'meals" I was there for.
I got 0 Breast Infections with my 1st and 2 with my second. I don't know how long I felt bad for but certainly the better part of a week. I don't know how often you can pump at work but try and pump and nurse a lot.-and drink water!
One thing I can say is I noticed I was less often engorged in general after my son got bigger and was able to drink all the milk I was producing!
My right breast had a benign lump since my first pregnancy and I went to a super specailist and she tested a sample of it, well she said it was literally a clogged milk duct but not to worry about it, when I'm done nursing one day my body will absorbe it on its own.
A note of interest is this is the side I get my infections on.
However, I've been nursing my son 2 1/2 years and he's happy to take either one I offer!
Hang in there, it gets easier.