Aw, sweetie, I am so sorry that you don't have more help. What you're trying to do is truly more than one person can do by herself. Everyone had good suggestions for you & I don't really have anything to add. I can only imagine how rough it must be to have twins plus a toddler. Your DH really needs to take next semester off, maybe the next year off. My 25-month olds would be destroying the house if I had to sit still for the 30 plus minutes it takes to nurse tiny twins. And I think you're right, those with singletons don't really understand, even if they think they do. You can nurse one baby walking around the house, either in your arms or in a sling/wrap, so no, not quite the same. You really are stuck in one place when nursing twins.
If you happen to be in the San Francisco area, I'd be happy to help anyway I can.
Also, you probably know this from having a toddler, but I found the 3-ish month age to be the hardest. This was a shock for me. Everyone said how much easier babies got as they got toward this age, how they started to become more regular in their habits & less fussy. Not mine. It was more like 4-ish months for me when the fussiness and crying calmed down. I remember we had a trip planned to Hawaii when the girls were 5-months old and I was freaking out about how I was going to take them on a plane because all they did was yell, cry, scream, but by 5-months, they were different babies entirely. People around us on the plane kept telling us how "good" our babies were, which is annoying in it's own was as if any baby is bad, but you know what I mean. They were pretty content.
I hope things get better for you soon & that you find some help.