Firs time ever i had severe ears pain when plane landed ystrdy.i was bit congested -(comon cold) now ears are blocked. why and how long can it last?

Probably congestion: This is a common problem when flying in combination with a upper respiratory infection, viral or bacterial. You can take medication similar to Afrin for no more than two days if the pain is acute. That will dry up your nares as well as allow your ears to drain. Follow up with your primary doctor if symptoms persist more than 1 week.