I'm sorry for your bad time at work.
Uhm, if you are deadly stuck, if your job is dead end, then you should be actively searching for a new one. I know it is quite difficult, but are you doing it? If the boss hates you then you could at least find a job where you can start over. If 3 years experience mean nothing to them then you would lose nothing.
Anyway, I think it is vital that you work on your relating skills. You say that you ended up crying, but that means you took what your boss said 100% emotionally and 0% rationally. So if you felt he was blaming you, maybe he was not after all.
When speaking to someone it is important to make sure that you hear and understand what they say, not hear the first words and jump to the conclusions that your mind suggests (and if you are depressive, we know what kind of conclusions they are).
I hope your therapy is aimed at this direction. I suggest that you get informed on the topic, there are many good books: if they don't solve the problem by themselves, they always help to use the t sessions better. This is what happens to me at least.
I really hope that these too many words of mine can deliver a drop of help :-)

The best of luck!