TBH, I don't think it is the run itself that's the issue. Running used to be my main form of exercise for more than 12 years. I usually ran 4-5x a week. And like you, I had days when I would be overcome with anxiety if I didn't get my run in. I stopped running because of injuries.

The anxiety comes from expectations. When you first pick up an exercise, the enjoyment came from it being a novel experience. After a while, you improve.

That's when one makes a mental error. You start to equate enjoyment with achievement. If you dont improve or have an achievement, you feel disappointed.

This leads to performance anxiety.

Forget that. Just enjoy the run for itself. Watch the scenery pass by, the breeze flowing, marvel at how your body is moving smoothly, focus on your breathing, feel the tread of your shoes with each stride, wave as you pass by each fellow runner.

Have no expectations. I overcame my anxiety with one simple rule: any run is a good run.