How do you deal with failure

I am using law of attraction to manifest things for about of couple of years now and it works. About two weeks ago i have applied for a summer job and got invited to interview. That was my dream job in industry i want to work in future. I never wanted anything as much as that job, so i was thinking about it for week. Thinking how well interview is going to go, how much money i am going to earn, how nice my cooworkers are going to be and i really felt like i already had that job. Basically tried to make as clear picture as i can what i wanted and feel that emotion.

Interview went great. Interviewer said it wast really good. I got call from the company today saying that i did not get the job :( But i have tried manifest it so bad...

Why LOA sometimes does not work and how you deal with it?