I am experiencing ankle swelling, ankle pain and unable to bend foot down. i missed a step and heard my ankle pop saturday evening. i woke up the next day with so much pain. couldn't put too much weight on it.

Needs to be treted: Even bad ankle sprains can become recurring, nagging problems if not rehab'd properly so you should have it looked at even if the pain and swelling subside. Initially, I would immobilize with a splint/brace until you can get it looked at. "Popping" can indicate a more severe tear or even an avulsion fracture.

You need xrays: a Lisfranc fracture/dislocation should be ruled out..

Be seen!: Definitely need to be seen to make sure you did not break your ankle.

Have it evaluated.: See your primary physician and get the appropriate referrals. Both a podiatrist and a foot and ankle orthopedist can help you out.

Rule out fracture: Your description of your ankle is suspicious for an ankle fracture or significant sprain. An orthopaedic extremity evaluation to include appropriate imaging is now indicated

X-ray: You need to go get an x-ray to evaluate for a fracture. I would go see an orthopedic surgeon.