What should I do about my swollen foot? To treat it with something. What should I do?

Swollen. The first right thing to do is to determine the cause of the swelling. For that you need to see your podiatrist. If it's from another area of the body the appropriate referral can be made.
Depends on cause. Gout? Infection? Blood clot? Trauma? If you don't know the cause, you need to see your doctor asap.