I think this is very close! You are spot on with your explanation of "used to do" - it is a habit you had in the past. "Be used to doing" is very close, but it can be used in the present or the past, and simply means a habit that you have acquired and perform often. For example: "I was used to doing the dishes, but then I got a dishwasher and no longer need to" <- this means that although in the past I often washed dishes, I no longer am in that habit "I am used to doing the dishes" <- this means that I acquired the habit of often washing dishes in the past, and that has carried into the present.