Hoo boy. I shouldn't, but I'm doing a some conjecturing ... !!! ... Go to the track and lay down a few 800s. Good for the soul. Be sure to run a good warm up. A couple miles, maybe a mile of striding the straights and jogging the curves. For the strides, I like to gradually go from jogging to striding, taking maybe 50 meters to get to mile race pace, and hold that for 50 meters. This morning was 4 x 1-mile for me. A low-volume threshold workout, but still 26 minutes total at LT. All easy now until Saturday's 5K. Just a few minutes at race pace on Wednesday, Thursday and Friday.
Looking back, perhaps I should have run that 5k. Judging by my friend's time, it looks like the new location/course was fairly flat. He won the race in 17:11. We both ran the 10k the week before, and I beat him by nearly two minutes.
Flyyy - My vote was to go ahead with the 5k, so I am happy you're running it. My all-time 5K PR came a week before my marathon PR. 16:04 and 2:40 at age 23. Very close to where you are now. Times and age.
Gordon T - A couple years ago I was experiencing hip pain while running, but found by concentrating on micro-adjustments to form, I could completely eliminate it. Side planks were also part of the permanent cure.
Pappy - Good luck with the knees. For me, THREE months completely off did nothing to help. It took gym time to realize any improvement.