Well done for keeping on going into work no matter how hard it gets. There is not much that's certain these days, but it is always easier to find a new job when you are in a job to begin with so hanging on in there is really important. Don't be too discouraged about rejections, I think it takes a while for most people to get to the interview stage when they first start looking. It can be worth contacting the companies who rejected you to ask for feedback as that way you can sometimes find out little things that make a big difference.

Amitryptiline is one of the older TCA drugs for depression. Generally, drugs in the TCA class are as effective as newer drugs, they just don't prescribe them much anymore because they have a higher risk when taken in overdose. The side effects can be a bit unpleasant but they usually wear off, they are a bit slower to act than the more modern drugs (anything up to 12 weeks) so if you are feeling some benefit already that is a good sign. I hope it does the trick for both the migraine and depression.