hi PN, I see your posts and see what a devoted mother you are and how much time and enthusiasm you put into your work and every other part of your life. I am in awe of what you pack into your life. You have done a fantastic job with your DS2. I think you ask alot of yourself and you should consider asking work to support you at a time you are obviously supporting them. I never advocate working from home with a small family as when you are there they want you but I think you could look at getting home early one or two nights a week, say at 3.30 / 4pm. spending a few hours with your family and when the boys are in bed, then putting in the rest of the working hours at the end of the day.
This would help to continue with breastfeeding as you will be there in his waking hours a little more and alleviate some pressure you are feeling because of your increased load at work. I am guessing your workplace is male dominated but you are the perfect example of the need for a flexible workplace and you are just the one to take the lead!