There's room for both the daughters need and her fathers needs as well. If doesn't have to become a forced choice, especially at this early stage.
But sadly, due to terrible tragedies where the mother chose the husband over the child, SS and everyone else will always need to know without doubt that you'll make the right choice and put your child before everything else.
Clearly you have to show that if it comes to it, your dd will be your priority, and you need to say it loud enough and long enough so there's is no doubt.
However, that doesn't mean you have to cut off your dp. There is treatment available and he needs help. And he needs to get involved in helping himself asap, before there can be any accurate evaluations of his future.
You've already done the right thing to have him move out of the family home. You need to keep dd safe and out of any situation that puts her emotional and physical health at risk.
I think you need to make it clear you're happy to work with ss to keep dd safe whilst DH gets help and to be open and realistic about his progress. And then walk the walk too.
What makes SS very nervous, and potentially swing into action in these situations, is when the family refuse to work with SS.
SS wants the 'innocent' parent to be the protector of the child. But if there's even a hint that the parent won't or can't fulfil that role, SS step in as the protector, and then you join the other parent as a threat to the child.
SS can be helpful and supportive of the family, but only if they have reasons to be.