The mental health system within the NHS is an absolute disgrace. Makes me so angry. The best thing i can suggest is to make a noise about this, put it all in writing because that needs to be taken more seriously since it needs to be formally recorded. Cite ethics and laws which are there to protect you. ( allegedly)
The service you are being offered is unfair, unethical and there is no continuity of care, if it was Cancer you were being treated for, it just wouldn't happen, so why is Mental health being treated this way? It all goes back to this old Victorian way of thinking that somehow mental health is a personality flaw, something that people have control over, that if you become mentally ill it's because you are weak or lazy or stupid and as a result funds are not reaching these services, they are not seen as a priority.

You haven't done anything wrong, you have been badly let down, this is no reflection on you.