A few things that have helped me (not medical advice, just my own experiences):
really try and consciously feel and notice when you’re holding your pelvic muscles tight, and relax them as if you’re having a wee-you won’t wee i promise!

that is the other problem I have - inherited from my mum, the anxiety about needing to wee every time you’re leaving the house etc, anxiety is all tied in with this stuff!
DO NOT CROSS YOUR LEGS it is sooo bad for all those muscles!!
sit with your feet on the ground at your desk, thighs parallel to the floor, 90deg to your lower legs. If you have to sit like a man to do it, do it!!
when weeing, really focus on relaxing your muscles, and notice where the tension is in your legs etc. I think public toilet anxiety is something not spoken about and defo needs to be addressed!!
I like to lay in bed with my legs in this position to open my hips and stretch the muscles:
obviously seek medical advice if you’re having really bad pains/problems etc, full disclosure I actually haven’t been to the drs about this, (I know I know, slap my wrist

) and I definitely should because now I have a chronic anal fissure. my smear tests are always very uncomfortable and it’s generally acknowledged I’m quite tense and tight by the medical staff
i hope this helps someone!