Well Jane, probably the best advice I can give you is to not panic. Try not to worry about your evaluation until you have it. In the meantime, if you want to keep the job, you could formulate a short explanation telling your boss that you realize you caused a disturbance (if you did) and are working on your problem. Put it on paper, then forget about it until the day of the evaluation. The explanation would make it a whole lot harder for them to fire you, again, if you really want the job. Remember, depression is a disease like all the others. If you have a good physician, he/she should back you up if your boss tries to use your breakdown as a reason to let you go.
Once you have that situation diffused, pat yourself on the back for dealing with it. Then start creating a plan for the future, but think in small steps; don't try to do it all at once. That would just create more pressure. If you're bored with the job and feel it's adding to your depression, start thinking about what you really want to do with the rest of your life. Dream a little. Ever thought about going back to school or training for something you've always wanted to do? Challenging, rewarding work can bring focus to an otherwise dark existence.
If your medication doesn't seem to be working, tell your doctor. If he/she isn't willing to adjust or change it, find another doctor. It took me many years to find the correct medication, and once I found it, it was like the sun finally rose on my life. I can't promise that kind of reaction for you, but hopefully you'll get more relief than you have been.
In the meantime, try to remember that nothing lasts forever, though sometimes it seems it may. Keep battling, keep getting up each morning, and make a plan for the future that you can look forward to.
I wish you happiness, and believe you will find it.
