Right leg stretch bring you’re other leg in to you’re thigh. Than alternate to left.
Can find yin yoga in Down dog app. And choose Yin yoga with emphasis on hamstring stretch. They are all free till May 1.
Good luck!
I do understand your pain. I am dealing with a similar situation actually. I am not an expert of human body so I can tell you what worked for me so far.
I try to apply a core principle of Yin Yoga which basically about not forcing your body to do a certain posture but simply leave gravity to its job.
So in other words, put yourself in the respective position that you are doing and don't force. If you feel pain just put yourself in a more comfortable position until you feel your body works but there is no pain or high discomfort.
I hope it helps and don't forget that the more you often you do it the better results.
Wish you a beautiful day ♡♡♡