Emily, this all sounds very familiar to me -- my DH was less than supportive of our breastfeeding from the get-go, and the extended-nursing thing completely blindsided him.
The part about fewer tantrums and more cooperation if she weaned just cracks me up! She's almost two years old -- she's going to have tantrums! Does anyone ever blame tantrums on formula-feeding? No, because both are considered perfectly normal.
The love life idea -- I think the best way to handle that problem is with actions, not words. Perhaps if you make an extra effort to be available to his needs in that department, he'll forget that he disapproves of your nursing. Or is there something else underneath that comment, some sense that he wants your breasts "back" for himself? Sigh. Don't get me started.
OK, the one area I would expect to be helped by conversation and creative problem-solving is the idea that his nursing toddler should be more receptive to him. My DH and I worked through this problem quite successfully. To his credit, while he wasn't supportive of nursing, he is a very good father and he wanted to do more to care for our son. And quite truthfully, like many securely-attached toddlers, our son quite obviously preferred me when he needed something. Daddy was okay for playing with, but Mommy was for everything else.
DH always encouraged me to go out more and leave DS with him. The more I did this, the better things got between DS and DH, and the less DH felt that his fatherlove was second-rate. I even, from the time my son was 15 months old, started taking occasional overnight trips away, leaving DS and DH together. These were necessitated by work and family emergencies that first year, but in hindsight I think it was a good thing for me to do anyway. DS learned to take nighttime comfort from DH, which over time reduced his night nursing, which I was very ready for. And he continued nursing until self-weaning at the age of 4 years, so in our case at least, none of these changes compromised our nursing relationship. And, for me personally, I found it very liberating after pregnancy and 15 months of very attached mothering to discover that I again had some independence and freedom when I chose to exercise it.
Since your DD is already staying happily with a babysitter on weekday mornings, why don't you try taking every Saturday morning to yourself, if your husband can be home with her? They can do fun stuff together and he can help her go down for her nap or whatever. And after a few hours of keeping up with her solo, I am sure he will be happy to see you come through the door and relieve him.