So sorry to see that you have suffered so much with depression. But I am heartened to see that you have gotten both the depression and meds under control.
There is 1 medication alternative that your MD may be willing to try: Topomax. A shrink friend of mine told me that he frequently prescribes it for patients on anti-depressants.
As for the things
you can do is start logging your food right away. Don't try to change your eating habits just yet, you want to get a baseline of what your current diet looks like. From there do some analysis using the great tools available w/FitDay. Are you simply eating too many calories? If so, cut back on portion size. Are you packing your diet with low quality carbs like chips, cookies, or white breads and crackers, then either cut them out of your diet or find healthier alternative. How is your protein? Lots of us substitute too many carbs for not enough protein.
That will get you started. Once you have an idea of what you need to change (and it will take a little time to figure this out) there are lots of great suggestion on how to modify your diet right here.
Then, try to get a little more exercize. No obsessive gym stuff, just longer walks, maybe a new sport (lots of us pick up new sports later in life, so being 42 isn't really a good excuse). But most important, find something you enjoy and hopefully a group of friends to enjoy it with. Take a dancing or yoga class, walk a dog or 2 or 3, helpout at a community garden. You say you are already pretty active, which is great! I suspect you just need to change the activities a little. Our bodies tend to get used to the same activity over and over again and stop being challenged, which leads to a halt in weight loss.
Keep up posted littlebit - we are here for you!