This is Dr. David
I am sorry you are having big toe swelling and pain.
you could be having an infection in the toe joint or septic arthritis.
you might need a course of antibiotics to see if that helps fight off an infection.
you should ask your GP doctor to refer you to an orthopedic doctor to aspiriate out some fluid out of your big toe and check for infections and bacteria and also uric acid crystals in the joint.
sometimes blood tests for uric acid can be low but you could still have a gout attack and inflammation of uric acid in the toe.
it doesn't sound like you have had any aspiration of the fluid out of the toe joint for evaluation.