Your post reads like a paradox full of contradictions. It also recognizable since I've been there many times. My conclusion is its not about the bike but the journey. Sometimes its a pleasant one, sometimes it isn't.To make sure my cycling is always a pleasant experience I make sure (as best I can) the benefits outweigh the negatives.
For instance, I know I don't tolerate cooler temperature so if the temp. is going to drop below my tolerance I won't go out. There's also roads, days and time of day that I try to avoid. To put it simply you may just be bored and need a change of environment, or may just need to take a break.