Recently i have swollen and painful foot arch after running, how should i treat this?

Sounds like: Plantar fascitiis. Plantar fascitiis is a broad banded ligament that runs from the heel up to the toe region and helps support the arch...You likely irritated it. Try wearing arch supports/orthotics. Ice the arch and perfom achilles tendon stretches. An antiinflammatory is a good idea as well. I.E Motrin or alleve. (stop running for a few days if possible to allow the tissue to rest.).

Ice and support: Usually this is due to a lack of support in your shoes. Ice the area to reduce the swelling and either purchase orthotics from your podiatrist or some form of support to aid you in running. Get out of those old shoes.