All managers keep paper trails. It is part of their job. If you are working on the items and issues she pointed out, there really isn't much more you can do. If you think being let go is a realistic thing, maybe you should just have a look around at other jobs, just so you know what is out there.

What I learned from being discriminated against at my job when they found out I was sick is, once they start making serious noie about performance issues, it is really best to have a plan you can fall back on. Just my own take from my life. Might not apply to you.

Hang in there!