Back when I did cross-country and track, we did shin splint prevention drills each day that basically involved walking about 20m first on our toes, then 20m on our heels, then repeating both of those steps with our toes pointing in and again with our toes pointing out.

I stopped running

I’m no expert, but for me personally, my shin splints went away immediately when I changed my running stride from heel strike to toe strike. I learned this when I tried running in minimalist shoes and the complete lack of cushion meant I would be bruising my heels. So, I stopped slamming my heels into the ground and instead land with the ball of my foot, absorbing the impact with the flex of the foot. I think of it as treating the cause rather than the symptom. It’s an adjustment, and I was a bit sore in some muscles I previously didn’t even know my foot had in there, so I had to work up to it a bit. Since I got used it though, I actually really enjoy the feeling of my feet and legs while running. I’ve also heard that the toe strike stride is less energy efficient, so apparently serious athletes never use it. If you’re running just for the exercise or for fun though, I recommend giving it a try.

Slow single leg heel drops.

Fore foot raises with your back and butt against the wall and feet about the length of your foot away from the wall.

The above are preventative strength exercises that should be done when you aren’t currently feeling shin splint pain.

Make sure it’s not a stress fracture.

Rest and stretch the lower legs muscles.

Reduce how long and how often you run for a while after your pain stops.

There’s no silver bullet for shin splints but the thing that worked for me was to ditch pavement for 2-3 weeks and basically slog up the steepest hill I could find on a dirt trail. I used to run to and from work, 3-5 miles 10-12 times a week, not a really balanced way to do things (no long runs), but when it’d act up I’d just walk to work and on the weekend spend 2-3 hours basically running up one big dumb hill and walking back down, try to get as much feet of gain per hour as I could (made it a little less boring to focus on that). Basically strength training for someone who would rather be running than strength training. Couple weeks of doing that and I was ready to go pulverize my ankles again for a solid couple months.

Edit: emphasis on walking down the hill, tremendous impact if you’re on some 25% grade, recipe for disaster if you’re throwing yourself down that thing for hours

First, you should stop or at least ease up on the running to give yourself time to heal. Second, work on your calves and ankle flexibility. Downward dog is a great calf stretch, try to keep your heels on the floor during the stretch. It may take some time to get there if you’re not very flexible. Third, if the pain doesn’t go away then you should see a professional to make sure you don’t have a stress fracture.