10 months is a short period of time, you really don’t even know him – the sober him. It sounds like he’s been drinking the entire 10 months and heading downward.
Aside from his drinking, which sounds like he’s not ready to stop any time soon. The bigger worry is why would you after only knowing someone 10 months, and knowing he’s an alcoholic who can’t ever seem to stop and stay stopped – would you think of still blending your families together? And in the near future, knowing his drinking has been going downhill why would even entertain that notion?
Don’t mean to sound harsh but he’s clearly not making you a priority in his life, so it sounds like you are far more into this relationship then he ever was.
Just because an alcoholic has not consumed an alcoholic beverage in a day or so doesn’t mean they are sober. An alcoholics brains is so saturated with alcohol there really are no sober days until they have not been drinking for months and months and their mind clears.
I would not call him, I don't make anyone a priority who's only made me an option.