I'm not going to move on easily after my boyfriend sends his dog back to the shelter
Why do you feel that way about his dog?
I've spent so much money on it already
The dog is going to be heartbroken being abandoned like that. They need a loving home to be at.
That's not going to happen. I took the best possible care of it, I'm its mom.
I'm proud of you that you took really good care of this dog, and I believe you should speak up for the sake of it. If your boyfriend doesn't want it, why not take it in for yourself? I'm sure the dog would love that.