@mmerchant He's inconsiderate of your well founded fears, and he allows you to be put in a terrifying position without your prior consent, and you're together only 6 months.
Its really unfair, and quite frankly weird that you feel the onus is on you to change. You got with him because he doesn't have pets, but now he's asking you to get a dog. This is so so wrong, for you. You like clean, dogs are NOT clean! You have a terrible, well founded phobia which will require the help of a therapist, not your inconsiderate BF that just decided to put you in terror.
If this is what the relationship is like in just 6 months, when you're both still trying to impress eachother and be on your best behaviour, imagine what it will be like in a year, or 2 years. I'd be afraid of what other serious boundary fires he'll be setting for you. It doesn't get better.
Please rethink the situation and put yourself first.
PS. I love dogs, have my own. I would NEVER force my dog on someone who was terrifed, that's abusive and frankly sadistic.