I'm always the one who sounds Pollyanna-ish but it's not to insult, it is just how I look at things.
I'm not depressed. I mean I feel that way sometimes but I've known clinically depressed people and I know it goes farther than a bad mood or bad day. I can't say "just go for a walk" and know it will be better.
I'm not especially cheerful either though. For those times when it's been really really dark for me, I make plans on how to change things. I made goals and did little tiny steps toward that goal. I guess what it did was distract me from what was going on but as that was happening, it also put me closer to where I wanted to be. I guess as bad as things were, I was moderately ok as long as there was hope. At least that's what I told myself and it seemed to work kind of ok.
I'm sorry you are going through this. Please do try to make sure your meds are good and also try to work through what's best for you. I know a person who is depressed, amongst other things, and he has learned to know his limits and what he needs from both other people and life.
Maybe it's time to try something non bike related. Or sign up for a hobby or volunteer or go hiking. I'm really not trying to sound all chipper about it but there might be something better for you (right now) than the bike. Sometimes it might mean forcing yourself out of your comfort zone a bit and then if you don't like it, try something else. You never know.
One of the things that I have been reading about in my counseling classes is "nature therapy." The idea that getting outdoors and moving can help emotional issues seems to have some real validity. I too, think that "letting go" of cycling for awhile is OK. I went through this last fall when I was having some severe anxiety from physical problems. But, I ramped up the walking and started doing yoga. It was a different routine, and it really helped.
Have you ever thought about taking a "Mindful Stress Reduction" course. It's based on the work of John Kabat-Zinn and focuses on using a variety of relaxation, yoga, and meditative strategies to "be with" your pain. I found it very helpful. I took it through the education department of a hospital and I still use the meditation cd from the program.
Another thing I tried was acupuncture. It really worked for the anxiety. It wasn't immediate, but within 4-6 weeks I was feeling better.
And make sure you have a therapist who uses a holistic approach. I never would have tried any of these things without some pushing from someone who knew about them.