What a hard time you're having. It can be a particularly difficult age for sleeping, unfortunately. I doubt switching to formula would make much difference to you. To be quite honest - it might just end up making even more work for you, you know?

It may be a developmental thing, or teeth, or both together. I was working full time at this age too - it's bloody hard and DS just needed boobies aaaaalll night. I hope you catch a break soon.