Suggest Treatment For Foot Pain

Hello, a few days ago my foot started hurting. The pain is right in the little dip like spot between the ankle bone the top of the foot. The vein there also seems to be bubbly. I don't have any swelling or redness, but it's very painful. Its a constant dull pain, but to walk on it gives a sharp stabbing like pain. Also, when I'm walking sometimes my foot just gives out on me and I have to catch myself from falling! When I rotate my ankle it pops. I appreciate any help on this situation, thanks for your time.