if you take the time now, and are very consistent, he will learn and then not need to be leashed to you forever. They do learn, in all honsetly he sounds confused, probably because like you said yourself, it is hard to always be consistent because you are busy. Does he jump baby gates if you are in the room with him? If not you can gradute from the leash on you to a gated room you are in and just watch him closely. Try to make a schedule when you take him out to do his business and try not to vary it much, he will get the point but there is no quick fix, it does take time and patience, even though it's hard.