First, it is unprofessional in the extreme to let your lack of passion affect your work. You are being paid for your job, you owe them the work, period.
Passion is like romantic love, it is all amazing at the beginning and the world is wonderful. But no one can maintain that over time. But you shouldn't divorce your spouse because things have gotten a bit routine and your job is the same way. It is the norm for there to be great passion at the beginning which eases with time. Grand emotions are, in the end, unsustainable.
How you cope is by first stop thinking that passion is necessary all the time. By making passion a big criteria for work, you are setting yourself up for failure as grand passions always ease up.
Not there is a differnce between not being passionate about your job (which often leads to having a more balanced life which is a good thing) and hating your job to the point where you would rather go to the hospital than show up one more day.
Sure there are times when it is time to move on to something else. But the point I want to make is that the grass isn't alawys greener on the other side. All jobs have boring aspects, all companies have people you would rather not have to work with, everybody gets tired of working relentlessly with no summer vacation! A new job will only fix this temporarily if all you have is a loss of passion.
However, if yo have reached the "I can't stand it here one more minute" phase, then yes search for a new job. Train for a new profession if that is where you want to go or just find a different workplace where the same job might make you happy with a new group of people. Try to analyse what woudl make you happier at work before you start searching or retraining. You don't want to end up in a worse place or with more student debt to train for another profession you don't really like doing. In the meantime, keep doing your job to the highest standard. Make it a point of pride to do so.