Maybe ask them to do something for you. Give those who act helpless the opportunity to reciprocate. Because they ask you to drive them to appointments, etc. doesn’t mean there isn’t something they can do for you. Do you need simple mending done? Maybe to sort out and organize your junk drawer? (Not that you CAN’T do it yourself, but would appreciate some assistance.) Relationships need to go two ways.
You need to strike a balance between mercy and justice. Pray and think it over, then set firm boundaries. (No, you won’t be available to spend all of every Sunday after Mass wining and dining them. You’ll still provide transportation to and from Mass, but then you have family time. Or you intend to spend next Sunday in prayer, or, “I have some personal business to attend to.” It says no better than, “MYOB!”)
If a person is truly toxic, separated yourself. Think, Abraham and Lot! Going in together sheep ranching was not working out. It’s time to go separate ways.