I am so sorry you are going though this. Do you think you could convince him to get his own place?
If not, I would say that one of the positives is that your son is 10. He's able so be more aware that something is off and you can also buy him a cell phone. My kids played sports and I made sure I always dropped them off and picked them up. My AH gladly let me drive them because then he had time to go drink (he never realized I purposely drove them everywhere).
I've heard that many times a breathalyzer can be used before visits to keep kids safe.
Your husband sounds scary - hopefully Lexie will chime in with wisdom on how to stay safe.