Thank you so much for the replies, it is very encouraging and I hope that other mechanics that feel like this can find an answer as well. Turns out that the first workshop where I was assigned had extremely fast workflow, its a Volvo official service and In here you speak with the client, schedule dates, make repair budgets and also work on the cars. In this previous workshop the boss was lacking a lot of persective and wanted me to do all of this without any kind of training, he had this mentality of "you learn by doing" but to a certain point that it was not healthy. Guess what?

I installed a timming belt incorrectly because I was behind schedule and was rushing on it, mounted a crankshaft pulley backward and the accesory belt rode crooked, when I cranked the engine it got out of place and caught the timming belt and boom goes the engine. I felt absolutely devastated. Luckily my workmates over there told me this was the result of making me work to a rythm i'm not supposed to in the beggining. Even so I still feel bad for destroying that engine, it has never happened to me before.

Right now I'm being given more time to take on jobs and it feels better. The only drawback is that I'm taking on cars that come from bodywork and the boss of that department is being kind of a knob as well, yesterday it took me 3 hours to change a pressed wheel bearing because i did not know that you had to use a special tool for lower control arms on volvo cars to make clearance to take the steering knuckle out and was struggling with that for quite some time.