As a parent and as a mindfulness instructor I am extremely for being present with my family. If I took time every day for my meditation practice I would most definitely keep my cool more easily during the full course of the day. But I am only human and it is not always possible, and being a parent is a lot about taking situations and challenges as they arise and trying to do the best of the situation at hand with the resources possible to you in that moment. I truly believe that sometimes loosing your cool is inevitable especially during the years with small kids who don’t sleep through the night. The lack of sleep is one good reason. But what I think is important is for every parent to take responsibility for his or her needs and to express them. If you need a 30 min run or walk to get your head straight, then make sure you get that time! If you need more sleep, make sure you get at least 15 mins on the bed, lying down, focusing on your breath. Do what you need to feel better, increasing your levels of energy so that you have slightly more resources available to be that mother or father you want to be.
In the mean time, please see this video where mindfulness teacher Alexis Santos offers 4 strategies for mindful parenting, maybe something will speak to you. Good luck!