Re: Is this the end?
I bet you can get through it. Just keep offering, keep pumping to maintain your supply as much as possible, and you can try the ideas from Kellymom for getting through a nursing strike: http://kellymom.com/bf/concerns/child/back-to-breast/
Even if your supply dips a bit, your body will pick right back up once he's nursing again. Supply and demand (in the absence of a hormonal situation like pregnancy) is an amazing thing. So don't stress about that too much.
ETA: The fact that he will nurse at night when sleepy is a great sign that he'll get back to nursing like normal!
Catherine, tandem nursing mama to Preschooler Girl 9/08 and Toddler Boy 3/11
Breastfeeding for 4 years and counting!