Hello Cara.
Remember that CBT is about changing thought patterns. Instead of missing your kids you should be thinking about what they are doing. You should be thinking about how much this time away will make you appreciate them. That sort of positive thought rather than how the job keeps you from them. Absence is supposed to make the heart grow fonder, not depressed.
You are doing very well, concentrate on the achievements. And there are achievements. And the job is important. Even if it isn't, find a reason it is. And please get rid of the associated memory. Please quit comparing, it can only bring up negative memories and you don't want them at the top of the pile. I could pat your hand and say quit the job, but you would not be happy and definitely poorer. And you know that is not how to win. You can not say " I won" unless you do.
Remember you like me have an anxiety disorder built on a lifetime of memories. Anything foreign can trigger it, even the common cold. It will pass, just like the cold. Give yourself some time. You know you really do expect a lot from yourself. Which is probably why you are progressing this fast but it is also going to make you cycle up and down.
A good three weeks? Are you comparing? How about, I had a good day, not perfect but good. That is a positive thought.
Davit.
PS, I am here for you, post often if it helps.