How do I calm myself when I feel like I'm about to faint or I'm overtaken by all the emotions inside me?

I believe that the answer that everyone can relate to when it comes to dealing with stress is engaging in activities that you enjoy (eg. hobbies) and/or finding some time for yourself to relax and rest. A more specific answer with regards to calming myself during an overwhelming situation in both my emotions and physiological state (fainting), I try to physically remove myself and find the closest environment where there will be no distracting stimuli and give myself time to recover. There was an interesting incident where I was taking hip hop classes during my adolescent years and due to my issue with low blood pressure, blood was not rushing to my brain, causing me to feel dizzy, blind, and had a few heart palpitations. I tried my best to remove myself from the dancing studio (outside the studio) and sat on the floor with one knee up so I can recover blood flow to my brain. Psychologically, having my extremities curl closer to my heart and head makes me feel at ease (similar to the fetal sleep position but being upright).

Sit or lie down (preferably lie down) on the floor or a bed in a quiet space for a few minutes. Think about something distracting, and take, long, deep breaths while doing so.

It’s always best to take a seat when you’re feeling a bit light headed. Take a second away from the world. Take a couple of breaths. Stand up and seize the day!

When I feel like I’m about to faint or I’m overtaken by the emotions inside me, i sit down and focus on my breathing. Once i’ve got my breathing on track. I remind myself of my happiest memories. If i’m feeling good enough, I will get up and put some music on to help calm me. Personally, i like indie music as it’s very calming. After i put the music on, I usually sit back down with my head in my hands in the dark and just think about the most positive things I can think of and, instead of thinking about what i’m currently going through and the bad things in my life, i try to focus on what i’m thankful for. I know it can be hard to focus on the positives but just things like food, a roof over my head, having an education etc. It helps to calm me.

Take a deep breath and try to focus on the way your body starts to move with each step of this process. Do not rush it, inhale and exhale as slowly as you can. When you're feeling calmer, try to remind yourself that these feelings are not you, they don't define you and you don't have to fight them. Just observe them, watch them fade away like clouds in the sky with every breath you take. Emotions are temporary and they're not going to destroy you or your soul, they will fade away, they have and they always do.