I'm sorry you are going through such a rough ordeal. Having been through getting let go from a job I had for over 4 years, I do know that it can be devastating. I'm not in a position to know if your work is shoddy or not shoddy. (You are in a position to know.) But it does sound to me suspiciously like your line manager may be an opportunistic bully . . . she has seen your tears and is aware that you are a bit fragile and seems to go for the throat in her criticism. I have had the experience of being let go from a job where my supervisors told me I wasn't quite up to snuff in a very nice way. They were right. I really wasn't up to the job. But they were as kind as they could be in the way they discussed it with me. So that's why I am suspicious that your supervisor is someone who likes to lean on a person who will take it very hard. It sounds like you may kind of believe this yourself. I say that because you seem despairing of any hope that you can have a decent relationship with this person. You may be right in that. It seems she has gotten to know more about your personal emotional life than it is safe to reveal to someone like her. Anyway you could get away from her without leaving the job? Don't assume the job is lost until someone warns you that you may be terminated. You could even go over the head of your supe and plainly ask just that, saying, "I need to know if I am in danger of losing my employment here."

It maybe wouldn't hurt to get some interviews with other employers. Are there other places that need people who do what you do? Does the flat require you to just have a job, or do you have to keep the specific job you are at, in order to keep the flat.

I hope things can be put on a better footing. You have been living in a state of feeling threatened for quite a while. That is unhealthy on a number of fronts.