This has to be the most frustrating part of any fitness plan. Hitting a wall or plateau. You are doing all your planned sessions, but are you eating well, sleeping enough and pushing yourself harder? Pushing too hard can be as bad as not pushing hard enough. Think about changing your plan.
Try a new class, do your usual gym session in a different order, be honest about how hard you are working. Do you lose interest after 30 minutes? Fine, then just plan to work hard for 30 minutes and then leave. Look at how frequently you train, what you’re doing and what you’re really doing! Then devise a new plan to include your diet – what you eat is key to your success. Are you treating yourself on the way home from the gym because you stayed for the full hour, even though it wasn’t that great?
Talk to a Personal Trainer if you need help. It could be well worth the investment to see the results.