First and foremost listen to your body. It certainly seems to be telling you that you are doing too much. Feeling weak or sore and losing ground in your performance are classic signs.
How much is too much can be very different from person to person, so its hard to say that this workout schedule or that one is going to be over training, but there are a few rules of thumb. Do give yourself at least one rest day during the week - no workouts at all. Do increase training volume slowly. Do listen carefully to your body - if you get hurt or sick take it easy and if you find yourself sore all of the time rest!
It sounds like you at the stage now where you should be able to recover just by taking a little time off and taking it a bit easier. Don't let it go too far though... you can get into a downward spiral that leads to having to take significant time off to recover!