Runner's Rut

A trend I've noticed with myself is that I get stuck in a runner's rut. I have no idea if that's even a term but if it's not then I'll coin it as my own. My own personal definition of a runner's rut is really hard to explain. It feels like no matter how hard I try, or how much effort I put into the workout, I get nothing in return. I hit a wall. Usually hitting a wall doesn't happen unless I get out too a fast in a race and try and pick myself back up towards the end.
The last few weeks during track I've felt really tired, sluggish and overworked. Even on the easiest workouts I could feel myself just hitting a wall. It's been almost 3 weeks and I'm still stuck feeling like there's no way out. I've tried different variations of running within the assigned workout to try and switch things up but even that doesn't seem to help. I've tried changing paces and running different splits a bit outside my assigned time frame.
Yesterday, at the very start of our workout, coach said something to me. He asked; "Are things just falling apart?" I said "Yeah, and they have been for a while." It's really disappointing to think about how much of a better runner I was just a short time ago during cross country. I feel like I'm on a constant decline and it's really worrying me.
I talked it over and there seems to be some hope left for me. I don't know the exact problem or the cause for that matter, but I think I can bring myself back.
Coach said something about how he tracked his progress with a heart rate monitor. He made himself stay within a range to keep his heart rate steady, running at a very slow pace. Within 2 weeks, he said he had cut off 2 minutes on each mile at recovery pace. I'm looking forward to trying it because it seems like it's worth it. I really have nothing to lose by taking it easy and trying something new.
As the saying goes, "Do what you've always done, and you'll get what you've always gotten." (372)