Sean–
If you attend a gym you could ask if any of the coaches have experience working with running technique.
You can take a video from the side and send me the link or post the link and I can look at it for you.
Seeing what you are actually doing is a big difference vs what it feels like you are doing.
Which run technique videos are you watching?
If you are working on mobility and not seeing any changes you may not be addressing the correct areas.
Here is one episode that addresses this topic.
Pro Episode # 21 – Pro-User Request Friday: Not Seeing The Change? You Need a Systems Approach.

It sounds like you need to relax your ankle when running.
Before you run do 10 reps each side of:
Foot flat on the floor and pick up your your heel up to have your laces on the floor and go back back through the rom to have your heel back on the ground. This equals 1 rep. Hold onto the wall or a pole to stay on balance.

Do you see an improvement when icing?
Have your done anything else to address the inflamed area?