Horribly inflexible, don’t understand why hamstring stretches don’t seem to help.

can’t tell in picture but i am in immense pain literally just standing there with my leg barely elevated, my right leg isn’t even facing completely straight forward. i don’t understand why even when looking up beginner stretches to get started, i can’t even do simple ones without feeling like im in excruciating pain not even a second into it. and with very very minimal range of motion like shown above. is it more than just my hamstrings? it can’t be this hard to start.