Allison–
Welcome to the M|WOD community!
Great to hear your excitement with beginning to use M|WOD.
Have you done search on the directory to see if there is an M|Wod provider in your area?

Good to hear you are remaining active.
First, pain can be processed a couple ways by the brain.
You have pain to get you to do something.
Determining where the problem originates and which movement(s) or position(s) are causing the flair up is key.  It could be something within the other 23 hours of the day.
Do you sit alot at work?

Taking ownership of your movement is what will give you the best long term results.
Continue to workout in doses your body can handle. You may need to adjust some movements or positions used during your workouts as things are normalizing .

Have you taken a look at Back to the Barbell?   
This will help you rebuild some movement patterns.
Are you seeing improvements in your sciatica?
Are you seeing improvements following the PRP?

If you are working on something and not seeing change you need to take another look at the situation.
Pro Episode # 21 – Pro-User Request Friday: Not Seeing The Change? You Need a Systems Approach.
Good to hear the couch episode is helping.
This isn’t a new issue so it will take some time to work through it.
Are you able to do 2 10:00 doses? One in the am and one in the pm?
Breaking up into 2 doses resets things.
Are you working up/down stream of where you are seeing the problem?
One to start with there are many that address the quads.
Episode 100: Quads or Spine? Quads!