Need help from runners...

No idea, but I'm having the same issue. I've been told that when you're increasing your distance, your short runs will frequently get slower too, but I'm not sure why.

Your first problem might be trying to do your runs at race pace. It's a mistake that a lot of people make- they try to run everything too fast. And believe me, I've been as guilty of it as anyone in the past, but you should only be running close to race pace a few days a week max. Most of your runs should be relatively leisurely paced to let your body recover. You wouldn't bench press hard on back to back days right? Running works in a similar fashion- you break your body down some, so you have to let it repair.

Some background on me- I've run multiple full marathons and put in many back to back months of 70+ mile weeks, so I have some experience if not much talent. Be patient with yourself, and maybe mix up the distance of your runs. Instead of doing 3 every day, do 4 some days and 2 others.
Oh, and mix it up. Maybe throw some sprint repeats into runs, or find hills, trails or something fun to do. And don't always bring a watch. Sometimes it's nice to just go out there and let your legs set the pace.

You are running all your training runs too fast. That works for a while until the cumulative stress overloads the body's ability to adapt. Then fitness begins to decline. If you want to continue to improve you have to run most of your training runs (80% of the training volume) at "easy pace" which is around 75% max heart rate or below.

Because you have been running at too high an intensity all the time your aerobic system is likely still underdeveloped and your pace may be very slow at the correct intensity. That is not a problem. Run the correct intensity for a while and the pace will improve.

SInce you are probably in an overloaded state right now you need to eliminate speed and run easy for a while until things begin to improve again.

Be sure you are not over training. I started doing two-a-days and i actually started going slower even though i felt fine. Recently (on 3rd week) cut back again from 6 days/week to 4 but added bike and elliptical. Cant say much about speed but endurance is better. Another thing i use to do was yoga. Did it for 1 month and it really helped my run pace. Im terrible about stretching afterwards and now go to a different gym and no yoga. One other thing. I'd re-baseline and start mixing up runs like others have suggested and work your way back up. The MENTAL aspect of running can ruin your runs if you let it. Run distance, time, run hills and sprints and forget pace for a while. If you go out for a long run and feel fast, go for it. Otherwise relax and focus on the long run. I cant schedule my fast days that well so after a 1mile warm up i know what the run will be based on how i feel.

BTW: Our pace looks the same. my 5K race is 23:50 and my training runs of 4 miles is ~30-32 and 5 miles ~42 minutes including warm up. Those are my faster training times. Many times if im not feeling it you could add 1 minute/mile to those times. Today i did 5.5 in 60 minutes b/c legs were sore and on dreadmill. No excuse, just didnt feel it and felt a need for a long slow run.

I'm always much more motivated when I run to feel rather than trying to beat a time. Maybe you just need to give yourself a break and run because you love the motion rather than trying to beat your time? give it a few weeks then start speed training again.

Just to reinforce what others have said on pace I run between a 6:30 to 6:45 pace in the 5K and an 8:06 pace in the marathon and my easy run paces are normally between 8:40 to 9:00/mi, sometimes slower since I run by heartrate.

Big time second on Mcmillan running- but make sure you're using paces based on where you are and not where you want to be. A lot of people go to sites like that, and say- I can run a 20 minute 5k, and my goal is to go 19 minutes- so they'll plug that pace in- which is asking for trouble.

He also has an awesome series of articles that really lay the physiology of running out that I highly recommend.

Your first problem might be trying to do your runs at race pace. It's a mistake that a lot of people make- they try to run everything too fast. And believe me, I've been as guilty of it as anyone in the past, but you should only be running close to race pace a few days a week max. Most of your runs should be relatively leisurely paced to let your body recover. You wouldn't bench press hard on back to back days right? Running works in a similar fashion- you break your body down some, so you have to let it repair.

This is exactly right. It took me a few months to learn this invaluable lesson. I think that that's probably true of most runners who are interested in getting faster. You're in good company.

I'd suggest going to a running site that can calculate training paces for you by entering in your PR race times, like http://www.mcmillanrunning.com/. If you use 24 minutes as your best 5K time, then 9.5 to 10 minutes a mile is exactly what you should be running on easy days, and you should run even more slowly on recovery days. Don't feel like you've regressed when you start running comfortably but slowly most of the time. You will be pleasantly surprised how better able you are to set new personal records on race day if you do.