I am so sorry this happened to you. I know how hard it is to even get an interview after a long employment gap and being a little bit older. Clearly, it was the university employee - not sure how anyone can doubt that, given what she said to you about not thinking you would be a good fit for the job in question. With that being said, do NOT EVER contact that psycho ever again. Also, do not contact the employer - that ship has sailed. I am so sorry there are such cruel people in the world, especially the corporate world. I can't imagine burning someone like that unless you called in sick every other day or were incompetent, which I am sure is not the case.
Even then, I still would be hesitant. Don't give up - with your experience and education, I am confident you will find a great job in your field.