Unfortunately being an addict gives people a big red button to hit whenever they find you disagreeable.
The road to recovery is hard and everyone stumbles, and it's made even more difficult when loved ones accuse you of succumbing to your addiction when you haven't and are struggling through an uphill battle, and unfortunately in a heated argument even loved ones might say stupid or hurtful things. You are in charge of your sobriety, you know when you've been weak or strong and you know the singular truth of whether you're sober or not. I've been in the same position as I'm sure many here have, you know your boyfriend is wrong, he can be wrong all day, but you can't let it impact you or your commitment to stay clean.
Hopefully he'll come around and apologize, but even if he doesn't, you're strong enough to endure one argument, you're strong enough to endure a breakup, you're strong enough to endure whatever life throws at you that hits that big red button trying to take you down a peg.