I can't say that I have a perfect understanding of how to self-regulate. However, I have put in a good effort to understand and navigate my emotions so that they don’t impact my life. People with ADHD struggle to self-regulate and tend to be emotionally deregulated at times. We (Us neurodivergent) have a hard time coping with emotionally distressing things, and we often react in a way that doesn't match the things that happened. Here's some important definitions before we get into the good stuff:

Emotional dysregulation: the inability to control or regulate one's emotional responses leading to significant mood changes, trouble dealing with changes, and difficulty working in groups. This can involve any emotions and can present as various degrees of the emotion.

Emotional regulation: This is the act of controlling one's own emotions. Being emotional regulation means that a person can respond to stimuli in a way that is appropriate and in control.

Self-regulation: one's ability to control their behaviour, emotions, and mental processes.

Here are some tips for improving self regulation and emotional regulation;

Journal: reflecting on your emotions and behaviours can help you to understand whether or not you are overreacting. Writing in a journal can help you to understand why you are feeling the way you are. Once you better understand your own feelings, you will be able to have more control over the way you feel and the way you act. You can also use journaling to track behaviours when trying to self-regulate. In order to properly self-regulate, you need to be aware of the things you are doing and how these auctions are impacting those around you. Try this… write down all the motions you felt in a single day and attach these emotions to both an event and a behaviour.
For example:
Emotion—> Event causing emotion—> resulting behaviour
Angry—> mother yelling at me—> slamming door
After writing this series of things, go a little further and decide whether these emotions and behaviours matched the event. Ask yourself what you could have done better or differently to address or deal with this situation.
Angry—> mother yelling at me—> slamming door = to extreme of a reaction
Angry—> mother yelling at me—> walk away and leave the room

Grounding Exercises: using breathing techniques to cope with negative emotions is a proven emotional regulation tactic. Breathing and grounding techniques can help you relax, reflect, and react to an event more calmly. Here are several helpful breathing exercises;
○ Ocean breathing: put the palms of your hands over both your ears. Close your eyes, breath in and out slowly and picture the ocean. The sound of your breathing will sound like waves crashing into the beach.
○ 3-3-3: take a minute and look around, recognize three things around you, take three large and slow breaths, and do three taps with your finger tips somewhere on your body… REPEAT. This technique is meant to help you focus on external stimuli rather than internal tension.
○ Reverse Thinking: identify the thought you are having that brings you tension and start thinking opposite about it. So if you are angry at something a coworker said to you, try to find something about the situation that is funny.
Regular Check Ins: it's important to regularly check in with yourself throughout the day in order to address any negative thoughts or emotions you are holding inside. Anxiety can begin with subconscious feelings or thoughts, and checking in with how you are feeling regularly can stop negative thought patterns before they start.
Speak to someone: finding a professional to speak to about your feelings can be very helpful. Narrative therapy with a psychotherapist can have many benefits. Also therapists can help you address unwanted feelings, and learn tools to help with emotional regulation and self regulation. Below are some benefits of speaking to a therapist about your emotions
○ Therapists are trained to provide tools in order to help their clients learn regulation
○ Therapy helps clients get in touch with their feelings
○ Therapy provides a safe space for people to explore their true feelings without fear of judgement.
○ Therapy allows clients to speak whatever is on their mind. Some people have trouble regulating themselves because they have so much pent up thoughts and energy.