It's a bit complicated to be in love with 2 men .. You are going to have to make a choice
Should I give my emotionally abusive husband a second chance now that he has entered treatment even though I have fallen in love with another man?
That is something only you can decide. If your husband does get the help he needs, do you think you will ever be able to trust him? I think you answer will rely heavily on your answer to that question.
You can not string both men along. It is not fair to either of them. This is a decision only you can decide.
Depends...
Did your marriage vows include "for better or worse, in sickness and in health, until death do us part"---or something similar?
If they did, I'd like to think you would honor that commitment.