I have had this/have this still! But its like 85 percent better. My pain/tightness was from constant sitting at my computer desk at work and sitting at home causing my muscles to weaken and tight up. What happened with me was...
I was stretching all the time but I didnt realize I wasnt stretching hard enough. I had one whole year of physical therapy but it wasnt until I took it into my own hands to really stretch hard and long at home that I fixed myself up. You really need to stretch as hard as you can and as far as you can and hold it for 30 seconds.
I would make like I was doing the splits and go as far as I could until I felt a deep stretch (which wasnt even close to doing the actual splits) I would hold this position for as long as I could a few times a day.
I also did my own variaton of this stretch
and any stretches you can feel in your groin/buttocks region. Make sure you try to stretch both sides of your body evenly as I didnt do that and ended up tightening up on the other side. The simple touch your toes while sitting down can can help piriformis if you go far enough and hold it.
Another easy stretch is too get in to the sumo position. Find how wide you need to squat to feel a deep stretch and hold this position for a least 30 seconds (or longer)
Everyday do all kinds of stretches and try to go farther with stretches everyday. Get super flexible, do weightless squats, go for walks when your bored and avoid sitting down as much as you can.
The last thing I did was make up my own stretches.. I would find stretching positions where i could really feel it in the area and just go hard on those. You dont have to do specific stretches you can make up your own. Find a position that you feel the deep burning stretch and go hard.
These things are amazing for going hard with your stretching. Seriously these might of had the single biggest impact on my stretching. You dont even really have to buy one just make one out of a rope or some shit if you want.