Its sad to say but poker has its ups and downs. There are a lot of donkeys out there in the poker world and they bring a lot of bad beats. The thing you half to remind yourself is that you will never half to be as lucky as they usually are to win. Remind yourself that you do a lot more winning then losing. Also remind yourself that, that hand is over, move on to the next. Seems hard to do at the time but thats what it takes to move to the next level.