Hi, From Past 2 Days I Am Not Feeling Good.

hi, from past 2 days I am not feeling good. All of a sudden I get a kind of feeling as my heart is sinking or someone is putting burden on it. Also I get shortening of breath .. I see a rapid increase in heart beat. I get cold so pale.. It continues for hours.. I had it yesterday and I am having it today too.. Its been 6 hours I am in same situation... sometimes my body starts shivering too.. I dont know what is this.. Please guide me with this