Panic Attacks, Increased Pulse Rate, Shortness In Breath, Sudden Feeling Of Coldness And Shivering

I dont know how to describe but i will do my best. I keep having night panick attacks where within the first hour of going to sleep i wake suddenly to a racing pulse short of breathe , bit disorientated and spaced out, i head straight to the window to get fresh air and control breathing , oce pulse has slow3ed down i go back to bed and go back to sleep. However I have never had one in the day until a few minutes ago. I have been sat at my desk typing a letter and all of suddenly came over very spaced out, pulse started to pick up and felt like this is it (know thats a little dramatic but its the feeling that i had, feeling a bit spaced out ive gone and sat outside, now back in the office i feel very cold and shivery? what is happening and what do i do. Im thinking the worst and having 2 very young children im getting alittle scared