Sciatica Support Group
Sciatica is a term meaning pain that originates from compression of the sciatic nerve, the longest and largest nerve in the body. If the sciatic nerve is pinched or compressed (perhaps by a bulging disc in the low back) a patient may experience leg pain--the classic symptom of sciatica.
I have done a bit of research on it, and it appears the muscle in the glute contracts and then irritates the sciatic nerve beneath or -in your case- going through it.
Perhaps try searching "piriformis syndrome" on Google. I've heard physical therapy can be helpful for this.
Sorry to hear you have had so much pain associated with this!
Best of luck!
Hugs!