DD1 was like that, but I didn't have a toddler to care for so it was no big deal. Can you wear her during the 45 mins between sessions? Better yet, if you are good you can nurse in the carrier. I'm not that good...
That sucks that DH is gone so long. This too shall pass. That's what I tell myself when I feel like it is all just too much. You are a great mama for wanting to give the best to your babes. How old is DS?