I hear you. This is a bit extreme, but it does sound like her behaviour is extreme anyhow.
First of all, may I ask how much support and contact you want/need from and with her?
If you feel that you need lots, then the following will not apply.
If you feel that you're actually pretty independent, and think you can carry through what you say, then this is one tactic:
Tell her when she may visit or call,
and tell her that any calls at any other time, you will not speak to her,
that if she visits at any other time, you will not answer the door,
that if she leaves anything outside the door, you will just leave it there or take it to the sidewalk for other people to pick up.
If she calls outside those times, just pick up the phone, don't say a word, and leave the handset on a table. Go off and watch tv or play a game.
If she visits, don't answer the door.
If she leaves stuff outside your place, take it all, even your favouritest dishes, her most precious porcelain, her grandmother's only portrait, (you get the general idea) and put it on the sidewalk.
Stand firm, don't be swayed just because it's something nice. Remember, the woman probably knows you really, really well, and knows EXACTLY which buttons to push.
Take the power back. She needs you, but doesn't see it that way, sees you as totally helpless, and thinks that you're the one who needs her. Show her that you aren't a helpless being, to be told what you want and need, and that you actually mean no when you say no, and that there are consequences.