I know you were a big cyclist before you got sick, maybe that's part of what's holding you back? Do you feel overwhelmed with the thought of having to do long rides? Maybe you're remembering how much energy it took or how tired you were. I say, ride for fun. Around the block. Down to the store. Whatever it takes. Don't focus as much on training or longer things, just go as much as your body wants to, even if it's only once a week! You might never get back to what you were doing before, but I think once you get the ball rolling, on a smaller scale, you might find your love for it again.