Congratulations, Edwin - this is a huge step! Irritability is definitely to be expected. Fun fact: so is some weight gain.
It'll be worth it for your lung health over the long term. Don't give in to the those crappy cravings. You're stronger than your cravings.
For the past week or so if I notice desire for a cigarette it generally passes in a matter of minutes. I've quit once before with vaping, but that has it's own risks too unfortunately.