Having your tubes tied isn't causing this. I have also battled depression (it's the dirty little secret moms never want to admit to or talk about it seems like which is so dumb). Anyway, my doctor told me there are lots of anti-depressants out there. She said it's like trying on jeans. A pair that looks fabulous on one person looks horrible on another. You have to just keep trying them until you find one that works for you. In addition, the one I used after he birth of my first child did not work for me after the birth of my second. My best advice to you is don't give up. You can and will feel better when you find the one that works for you. And when you are feeling better you'll be able to look back and say "wow...I'm never going back there."
I'm happy to correspond with you more about this. So feel free to email back. So obviously you've had your third baby (I remember all of your frustration with being sent home, etc.). Did you have a boy or a girl?
Good luck E....believe me you're not alone here!
L. H
PS...I'm a sahm to 9 and 5 year old girls married for 11 years.