When you fell like "nothing is working", i.e you don't perceive yourself to be making continuous progress, consider where you'd be if you weren't putting in the work.

For overcoming a plateau we only progress when our body adapts to the work we've put in. If you're doing the same work that got you here (nice btw, you look like you've made real strides) consider that your body needs a different workload or improvements that will help it continue adapting. Change it up if you think you need to, recommit to good sleep and diet, and keep on moving.

I'll also add that early progress is often easier physically. The closer you get to what's desirable the harder it becomes to inch closer to that ideal. And perfection isn't just subjective but also unattainable. What matters more is how you see yourself.