It can be a tricky thing and take many different approaches or tries, but eventually your son will wean more and more or at least start getting more liquids and solids than now. Neither of my children took a bottle (3yo son, 16mo dd) and interestingly they approached sippy cups, regular milk, straws and solid foods very differently. My son couldn't use a straw for a long time, LOVED regular milk from sippy cups (though the transition to cups and sippies was gradual), and ate a lot of solids. My daughter has used a straw since she was young (maybe 6 months? only water), mostly just plays with sippies, eats solids like a bird and is a very social eater, but absolutely hates regular milk, no matter how it's given to her (except a little in milk or to dip graham crackers into). So, I just want to remind you that each child is different. They all do things in their own way and own time.
As much as you want to get away with your hubby, easing your children into different life changes is so important. It sounds like you've been doing a great job being there for your children so far and I understand your desire for breaks. But, I have to agree with a few other moms who suggested taking smaller, more realistic breaks for now until your son is in a different phase, can be away from you for awhile without feeling abandoned and eat and drink from another caregiver without issues. For now, you could do weekly date nights or do more family activities where you find time to be with your husband more, even with the children still around.
It may take a few months more, but remember this is just another phase! While you're in a tough time, it's hard to see that. Think about what you want in the long run. In a year from now, you'll look back and hardly remember how difficult this issue felt, but you'll remember how you approached the situation and if you are pleased with the decision you made.
I hope this made sense and helped at least some.
~N.