My feet cramp inwards if I bend them

I feel like I’m going insane because I don’t know what’s wrong with me. It started when I was in the military about 6 years ago, every time I stretch and bend my feet to be parallel to my legs, they start continuing to bend inwards and it feels like they are contracting inwards. And when I go back to standing normally they’ll try to continue to curl inwards and the pain is on the same level as a period cramp, it takes between a few to several minutes of my feet being in pain even with me standing flat feet on the ground. I’ve been told by the doctors in the army and the Sgt’s to curl my feet into it, but that makes the pain worse makes my feet get stuck in the curl, and nothings fixed. Every time I try to stretch my legs and work on improving myself, do yoga, or work on the splits, I have to be careful. The worst part is even when everything is fine, if I dare to stand on my tip toes or bend my feet down I can make it happen and then I’m in pain.

I have no idea what’s wrong with me. Soreness isn’t this painful, and sometimes I’m practically screaming in pain, trying to massage my feet, or slamming them on the ground just to make the pain go away. Does anyone else have feet that will just make life hell out of nowhere just because you want to attempt to stretch????