Just because you saved a life doesn't mean you have to hang on to the dog until it gets adopted. The shelters exist to take in strays, provide them with care and safe boarding, and get them into homes. My thought is that, if you can't take care of this dog until you find it a home, you need to take it to a nice no-kill animal shelter where they can neuter him and take care of him and find him a good home. (I've never experienced any dogs actually getting kennel cough from the bordatella shot.?)

Why is your boyfriend upset? What does he want you to do, release the dog back onto the streets?!!! You saved a life today!!! If your boyfriend is upset with you and threatening to end your relationship, simply because you are a humane and caring human being, well, IMHO, maybe it's best that that camel's back got broken!!!
Please clarify why he is upset!