Growing up, I never had any guidance for how to manage moments of pain - (I was busy managing everyone else's) so I hope that this can be helpful by showing a little of my process too. I tend to feel my emotions in sudden strong waves. I used to really struggle to manage those waves and felt out of control when they hit (Sometimes I'd even have flashbacks and/or dissociate. I never pursued a diagnosis but at one point I had a lot of the symptoms of C-PTSD).
A dark emotion can lead to feeling the need to 'do' something - to need someone with us to calm us, to make a sudden rash decision, to lose our temper, to physically escape/disappear, to bury our pain in alcohol/drugs/food/compulsive exercise/sex, to want to hurt ourselves...
None of our coping mechanisms are shameful. Some are less constructive for our long term wellbeing, but they were always you doing the best you could in the moment. Whatever your trauma has led you to do and however 'bad' you think you are, you are loveable and you deserve to heal.
If a wave feels too powerful to handle alone, it's so strong and wise to ask for support. Please do that if it feels right for you. And we can also practice self soothing as a habit so that when we are in a dark moment, it feels like we have a choice of how we would like to process that energy, rather than feeling powerless unless someone/something outside us is able to be there. It's about empowering ourselves, never about denying our needs. So the process I am going through right now as I experience some challenging emotions is leaning into the pain, floating into it and allowing myself to feel. Trusting it, knowing it will pass. All that's really happening is some sensations are moving through my body, and any lessons that are being learned through this process will reveal themselves in time.
Some old thoughts have come up and tried to attach meaning to the sensations through my body. I am quietly letting those stories fade away in the present moment.
I don't even have to totally believe a more positive perspective, just be open to the idea that those thoughts are not the truth.
If a thought feels particularly real you can deconstruct it lovingly e.g.
"You know you did your best. You don't have to internalise their judgements of you. You are kind and good"
"There could be another reason why they acted that way. You don't know that it meant what you are afraid of"
"Maybe that's true, but the deeper belief that is hurting you is that you think if it's true you won't be able to cope. Yet you're still here. You've had your fears come true before and recovered and found happiness again. This external thing really doesn't limit how much happiness you can experience"
Or you can go beyond thoughts altogether and focus on the here and now. For example:
Focus on the breath
Notice all the objects in the room that are a certain colour
Listen to the sounds going on around you and just be present with that Feel the energy in your body focusing on one section at a time from your toes up to your head
Include gentle movements that release energy such as stretching, dancing or singing
Hold yourself - wrap your arms around yourself, place your hand on your heart or your belly, wrap yourself in a blanket etc
Repeat a mantra. [My favourite is "I am loving awareness"]
It might be really painful right now, but it will pass. It's okay to feel this way. This is temporary. You've got this.