I totally agree with Eskielover! That woman is not in her right mind and you did well to get out of her house when you did. No need to feel guilty. You DID NOT abandon her or let her down.
There's no such thing as "baby bi-polar". Either you are... or you're not!
You said that she tried to change you and you went along with it. WHY?? Aren't you happy with yourself as you are? Granted, we all can do with some changes and growth, but who is she to try to mold you into someone you are not?
For your own sake, you need to stay away from this family altogether but most importantly, you need to find out who YOU are, what YOU like or dislike about yourself and then set about changing what YOU don't like... and strengthening what you do like.
Get to know who you are and what your personal boundaries are. When you find your boundaries, be sure to guard them with your life. NO ONE has the right to change you except YOU.
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Psalm 119:105 Thy word is a lamp unto my feet, and a light unto my path.