I hit my lower shin pretty good on stairs. i can hardly put weight or move my leg without severe pain. its very swollen to my ankle but no bruising?

Ice it: If the injury occured within 24 hours otherwise i would recommend hot compresses. Antiinflammatories can be of benefit if not contraindicated. If pain persists after a few days visit the doctor.

Shin: If it has been a day or so it is time to seek professional help . I n the meantime ice compression and antiinflammatories if you can take them.