I'm glad you're feeling better. It was nice of you to send me a thank you card. I actually treasure notes like yours, and keep them in (as my friend Amanda Brown calls it) the "I don't suck box." On really bad days I read stuff from it for solace, and to reassure myself that I really am doing my best, and some people appreciate that.
BUT I must admit, none of the notes I've previously received, in 15 years of doing this, came on a card with a picture quite like yours: