Loss is the bad thing and noone want it to show up. But the key thing is , if there is exist a winner so it must has a loser with it. So When you're losing , someone else is winning. So learn how to become that winner is the way to deal with loss.
Yes if we get loss means someone will be in profit, but if you get lost in trading you will learn something, and it will help you how to do safe trading in next time.