I'm many ways I am just like you. Trying to improve average speed and distance without any real short term success. But I did manage to develop tendonitis in my hip, which really bunged things up. But I did manage to improve one thing and that is my tracking of progress. It didn't feel like I was improving but my average mileage rate did improve from 13 minute miles to 11 and 12 minutes miles. I was able to lengthen my runs up to 4 miles admittedly with slower runs. Tracking is really necessary for me to understand how things are going. I'm almost ready to start running again, but this time I will keep close track of my t runs and my rests so that I can assure my actual improvements and even more importantly track my days off. But I can walk any time. It just doesn't seem to hurt anything. And the dog loves just running in the forest off leash. That also delights me.