G.S.
Hi E.,
First I want to say congratulations on your strong desire to do what is best for your little one - often times our priorities get jumbled, and we may find ourselves putting work above our children and then later regretting our actions.
Pumping at work can be difficult - but it sounds like you've mastered it! If you haven't already, get in touch with your local LeLeche League leaders for help with timing (whether to increase the period between pumping sessions), help with what you are perceiving to be stumbling blocks with your co-workers and boss, etc. If you don't have a local chapter, they have a website that may be of assistance as well.
As a mom of 6 (10 and under), I'm no longer working outside the home, but I did pump at work when my second child was young.
I wish you and your family all the best,
G.