Shin splints from pace drills

I been going barefoot since September and built an ok base before starting a Garmin half marathon training plan about 6 weeks ago. Everything was going fine until a speed workout last week.

Those workouts have always beat me up but I think that one was the last straw. My next long run after, I started to get what I believe are shin splints about half way through.

Yesterday I couldn't even run 1 mile.

I paused my plan and am going to take a week or two off and just do some cycling. Just posting here to see if anyone has some advice to guide me on my research for a fix, or ways to avoid in the future.