If the lady you’re interested in is currently dating a jerk, it’s going to end badly for her. It’s just a matter of when.
Thing is, no matter how right you are in your assessment of him, you won’t win her favor by trashing the guy. You might even drive her closer to him. Just let it play out (it’s not like you have a ton of other options), and be the first best alternative when it blows up….because it will.
Meanwhile, put yourself out there, as you are with the website and cycling group. Maybe you find somebody. Maybe you don’t. But you don’t make yourself more attractive  to either the lady at hand or to new people  by pining for something that’s currently our of reach.
Regarding the job, discretion is big. If you’re that unhappy, explore other opportunities. Just don’t broadcast what you’re doing  which is really easy to do at the coffee machine or after-work drinks. There is no confidentiality on this sort of thing.
Plus, any industry is a smaller world than you think. People talk even when they have a duty not to. You‘re speaking volumes about what you think just by looking elsewhere. No need to trash your current employer. Just makes you look whiny and bitter  neither of which will potential employers find particularly attractive qualities.
In both romance and career, you rarely lose by taking the high road.
Voice of experience. During my working life, I made a lot of the mistakes I’m cautioning you against. I saw all of them.