Its math bro. Playing mtts mean first that:
You will lose much more than you win.
You will go through long periods without winning anything, even if playing well.
Also, you need to know what your ROI (return of investiment) is.
MTTs are volume, so, what percentage of tourneys you usually get back at least your buy-in? 10% 25% 30%? Do you play big field tourneys? small fields?
It will all influence. You play long hours just to get a min cash? Table selection to avoid these and if you do not handle playing many hours, select smaller fields with short LR.
Having that in mind, losing is just part of the game. Now, losing and not looking for your mistakes/reviewing a tourney you felt anxious/nervous after will only get you stuck on the non-winning side of the game.
Hope it helps, and relax because poker is measured in long term results. losing now and letting it affect your feeling towards the game only makes it harder to learn and improve.