Well, it
is very difficult to approach peace soon after or during emotional turmoil. Since you can't just delay your surgery and try to create distance from your pain, you'll have to face it... somehow.
Distraction is a decent antidote for pain, and heavy physical activity helps make a body happier. They work hand in hand. Since yoga doesn't provide either of these, it's easy to understand why it didn't work out. I'd suggest that you should do something that doesn't leave much room for thinking about things that aren't related to the task at hand. As for what that could be for you, I can't really say, since I don't have much knowledge about your fitness and expertise. Tennis is easy to get into, sport-wise. As for martial arts, Boxing, Kick-boxing, Jiu-Jitsu, Judo, Muay Thai, and a few others offer action much sooner than most others, though you may not be looking for something requiring much aggression, which would rule these out.
Video games are also a good distraction, but they suck the life out of you rather than putting life back into you. If sports or martial arts aren't viable options, video games are readily accessible whenever you need to get your mind off of something!
What I do when I'm unhappy (which is unsurprisingly often) is I just embrace it. To me, depression is not something that I have to overcome or defeat, but rather, it's an inevitable part of me. It's there to protect me from further harm, and if it fails then I can cry. Crying is a great release, and I always appreciate being able to do it. I don't really recommend my point of view on depression, and I would love to get over it someday, but at this point it's really just a part of my personality.
When or if I do escape depression, I will have learned to accept pain and let myself feel and experience it as just another set of emotions and irrational thoughts. When emotional pain tries to take over, it really helps to become objective, if possible. It's difficult when one is in pain, but to see pain for what it is helps in the process of enduring it with grace.
I wish you well, and I'm sorry that you have to go through this.
