People are imperfect. We all are. It can be hard, but the only way to deal with this is to focus on people's positive qualities and to forget their negatives. If a person has ten bad qualities and one good quality, focus on the one. Loving people and being happy can only come about when we see only that which is worthy of praise in a person.
Here's a story about Jesus which illustrates this: -
"It happened one day in the time of Christ--may the life of the world be a sacrifice unto Him--that He passed by the dead body of a dog, a carcass reeking, hideous, the limbs rotting away. One of those present said: `How foul its stench!' And another said: `How sickening! How loathsome!' To be brief, each one of them had something to add to the list.
But then Christ Himself spoke, and He told them: `Look at that dog's teeth! How gleaming white!'
The Messiah's sin-covering gaze did not for a moment dwell upon the repulsiveness of that carrion. The one element of that dead dog's carcass which was not abomination was the teeth: and Jesus looked upon their brightness.
Thus is it incumbent upon us, when we direct our gaze toward other people, to see where they excel, not where they fail."