Yeah I'll just echo what's being said around here already. Take it easy.
I'm an ultramarathon runner so speed isn't usually my thing however I can still rip off a 22-23 minute 5K if I want. But still training runs should be just that...training.
Last week is telling of my 'usual' regimen as I ramp up to run a 100 miler in November
Sunday 12.5 hilly trail miles at 12:30 pace with friends
Monday Rest
Tuesday 4.1 miles trail run with hill repeats 12 min/mile(warm up mile 9:30 pace, 2 miles of hill repeats, cool down mile 9:30 pace)
Wednesday 4 miles around my flat neighborhood 9:10 pace focused on 'speed' and good form.
Thursday 5 miles on new to me trails 12 min/mile pace again
Friday Rest Day
Saturday 18 mile very hilly trail run at 11:30 pace
Sunday 6.5 miles at 10 min/mile recovery run
None of those were hard miles except towards the end of my 18 miler as I got fatigued but otherwise most of your runs should be easy to you pace. If you can't hold a conversation with a person next to you, you're running too fast. I concur it sounds like maybe you've got yourself overtrained. Take a few days off, let everything heal up and then start up again but make an effort to slow it down.
One of the best runners I personally know, who runs a 2:35 road marathon and a 16:20 5K, will only do speed work maybe 2 or 3 times a month. He swears by NOT doing speedwork but instead focuses on endurance, and good form/running economy.