I am starting trading some month ago.Bought some alta coin but now all alta coin are down and i donot understad what can i do?I get a big lose if i sell this.So how control my mind ? 
In trading it takes patience and tranquility in emotions if you buy at a high price then the price down is normal, many people who experience it like you better calm down and be patient waiting until the price goes up again.
Right, patience is needed in trading coins but still holding emotions are sometimes hard especially if the price keeps going down. What I do is just set my order whenever I trade. I don't watch over the price so that I will not be displeased if the price keeps going down. I go back to the exchanger after an hour just to check if my order is processed.
In trading, if you are not able to control your emotion you will always end up selling your coins at lower prices and loss the opportunity or the chance on earning good profit.