I went through this and was so exhausted and tired that I gave up (I physically couldn't do it anymore) and did sleep training. It worked, but it was brutal on my emotions to hear that amount of crying.

For the vomiting tip - don't feed close to bed time, it's ok your baby isn't hungry (assuming you fed all day and leading up to an hour before bed time).

Anyway - I always think to myself that in hunter gatherer societies babies aren't put down and there's always someone to be with them - but that's not the world we live in now, and while it's great living in a house - it has it's downsides too and I think one of them is is these types situations with young children. Where 2 parents aren't enough.