4 month old closed displaced medial malleolus o right tibia currently non union misdiagnosed initially should i still be weight bearing which is painf?

Depends on fracture: Typically non-unions are treated surgically. The hard bone is removed and a screw or plate is applied across the fracture. Alternatively this could be treated with bone stimulation devices over 3 months along with non weightbearing

Fix it.: If you have a displaced medial malleolar fracture that has not healed (in part likely because it is displaced). You might want to consider having fixed with the very real likelihood if returning to full activity by 8-12 weeks. At 22, you are too young to not have it corrected and to have to live with any long term restrictions.