Thanks for your question. I would like to offer clarification that you are not toxic, but that your emotional reaction may have been out of proportion to what was warranted in this given circumstance. We want to be careful to separate our emotions from who we are. Our emotions do not define us nor are we defined by our emotions. I think the initial key is in becoming emotionally aware before your emotions reach their peak intensity. There is always a slow progression of feelings before they become unmanageable. We can often prepare ahead to deal with difficult emotions when we know certain situations are triggering, so in the case where we know, we might become activated, develop a plan for managing the situation before the circumstance unfolds. In cases where emotional reactions are unable to be planned for, having a road map to deal with them is helpful. Most often you want to learn to set boundaries with yourself and to take a time out when you are initially activated. You then can take time to reflect upon your feelings, journal, or even engage in activities that are distracting from your emotion. The key is to distract yourself until your emotions become more manageable and controllable. Doing activities to soothe yourself, such as getting a massage, taking a bath, lighting a candle, etc. are great skills to implement to reduce reactivity when initially activated. Once more controllable, you will very infrequently regret your response. It is okay to have an urge to act when emotional, but if you cannot separate urge from action, then it is problematic. Take a deep breath as another strategy to buy time prior to responding. Anything to slow down the response so you can process its implications is key to then provide a response that is not later regretted.
I think the other key is being able to consider the risks and consequences prior to acting. If you can delay a response five minutes, then ten minutes, then longer, that might help you to think through the response and whether it is reliable and trustworthy. Its reliability will be determined based upon how you feel as time progresses about the same issue. Thinking about what you might regret if you take the risk to act now might prevent later regrets. After all, the only moment you have influence over is now.
I think there is so much more that can be said about this topic. Remember start by grounding yourself to come up with a response that combines reason with emotion rather than just offering an emotional response. If interested in learning more, I highly recommend Dialectical Behavioral therapy, which is a therapeutic approach that emphasizes distress tolerance and effective emotional regulation to create more meaningful relationships with self and others.