Boston, You've been through so much hell, you need to do what feels right to you. You were taken with that house & it sounds very appealing. Your bf should be supporting what is most important for you, not discouraging you because of his own selfish reasons. If he cares about your well being, he'll get over the problems it might cause him.
You can still have your apartment and a dog again down the road. I know you feel worn out, but you're still young & can turn this all around. Please let us know how it's going.