70 miles a week isn't too much if you have worked up to it slowly.
I think there are two likely sources of your problem.
First, there is a good possibility that you are having fit issues. The knee pain is very likely due to your seat height being incorrect, and your other pain could come from fit issues as well, especially if you are running clipless pedals. You local bicycle shop should be able to help you with this, as long as you ask them for someone who is experienced in fitting bicycles.
Second, cadence may be an issue. Aim to ride at 90RPM or greater for the bulk of your ride.
Finally, flexibility can also contribute to this. I had asymmetrical hamstring flexibility when I started, and that caused me to sit crooked on the bike and led to some weird back problems.
If you don't get relief, a good physical therapist with bicycle experience can work wonders.