I have pain in my left instep, which is causing me to walk with a limp, because of the pain and lack of support there. what should i do???

Instep: if walking is difficult several things could be causing it. Fracture, plantar fasciitis, contusion. You should be evaluated by a podiatrist and an x ray

Instep pain: Many structures insert at the instep, or arch area. Pain in the instep means keep weight off the area/foot. Look up Plantar Fascitis Posterior Tibial tendinitis, and Tarsal Tunnel Syndrome. Should follow with specialist if pain persists.