Severely sprained my wrist and can't move fingers. not broken but hurts horribly.

Seek care : Lack of finger movement may be pain or more complex. You should seek care and see your MD. This needs attention. You said not broken, was that based on a X-ray and is your wrists in a splint. If so have to ensure splint not too tight to impair circulation. Best of luck

Tendon injury: this is most likely a tendon injury since you cannot move the fingers. There are other soft tissues in the wrist which also could be injured. You need to see your physician and perhaps see a orthopedic hand specialist. You may need other imaging including MRI. Be sure what the damage is.

Wrist sprain: May indicate a severe injury not just a "normal no fracture" X-ray. Wrist ligament injuries can be complex and if associated with significant swelling and pain one need to be evaluated with a hand surgeon. Don't be satisfied with "no fracture" seek treatment.