What are some steps I can take to become more of an approachable and understanding person?

Hi, thank you for asking this question. So many others are on this journey with you and experience difficulties with being limited by their mindset and feeling overwhelmed, unable to manage intense emotions.

It is clear you have insight to a goal for personal growth. I appreciate how you are observing something about yourself and connecting it to how its impacting your life and interfering with your goals in relationships. We may not have caused all of our own problems but we have to solve them anyways for our own sake. You brought up similarities with other relatives, there are many paths to how we get to be who we are and to explain our behaviors. Some people have a biological disposition to be more reactive, this would be the hot-headed nature you have described. We also have models for emotional expression, what did we see other relatives do with their emotions? Emotions also have to be experiences and tended to. We need to allow space for them, they have an important function in our lives. There is hope in that with recognition and developing skills, we can then learn to manage emotions and minimize consequences from the emotions we experience. In addition to this, we can also work to reduce our own susceptibility to experiencing negative emotions by taking care of our health since emotions are biological responses to our environment. We can improve our resistance towards anger by eating healthy, exercising, avoiding substance use, sleeping and making sure we are getting routine medical care and managing health concerns.

Everyone has beliefs that influence and drive our behaviors. The my way or the highway mindset sounds inflexible, and we know rigidity can lead to us feeling less happy. There are so many things in life we don't have control over, adaptability leads to experiencing more moments of joy. It's important to re-examine the beliefs we are raised with that have been passed down and modeled for whether or not they lead us to the life we want to live. All or nothing thoughts also lead to unproductive behaviors, and high levels of distress as well. 

You sound very motivated to make some of these changes, this is the first step. The next step is to identify what exactly your goals are and how your emotions and thoughts fit into reaching your goals. It helps to practice self-compassion, sometimes it's more about bringing awareness, practicing acceptance and reframing our thinking to better control our responses, than it is changing who we are. Congratulations on taking the first step by inquiring about how to make progress towards this area of growth for yourself. I hope this information is helpful for you to start taking more steps towards your goal.