Bipolar Disorder Support Group
Bipolar disorder is not just a single disorder, but a category of mood disorders marked by periods of abnormally high energy and euphoria, often accompanied by bouts of clinical depression. This is the place to talk about your experience with bipolar disorder, learn from others' experiences, and find support.

Yes, people can, indeed, be mean. May a flow of nice people rise to comfort you.
You need to stand up for yourself.
I think that either you do is either to make that final break or get some professional help re why your view of the relationship is flip flopping so often.
Unless you take action I think this situation is just going to continue and I'm not sure that we are helping you much.
Perhaps you need to consider another therapist? Otherwise this is simply going to continue.
If you are looking for just sympathy that's fine, but if you are looking to actually change the situation I'm not sure sympathy is actually helping you - actually the opposite as it's more like an enabler.