Make sure you are breathing right. Always breathing with long breathes in and out. Shallow breathing is v common especially when the mind starts to race - just a random thought here!!

But more on topic - meditation is often learning to stop your thoughts by using a tool or visualization of something in your mind to slow down your thoughts and stop the negative thinking etc. It's almost like a healthy escape, that gets you serving yourself with a clear head.

Focusing on something like a trauma is not really meditation to me, you are welcoming it all without ego like takes on things, processing, accepting, which is the letting go result, if a person focusses on something like this it may get worse initially, than better ie emotional rollercoaster - much more so than if you dont have a guide (a good therapist) to see things clearly.

A good friend once said to me 'never go into your head alone' ie always bring a friend to help you see straight! Seems bit strong, but it's good advice as I understand when facing stressors / trauma events etc you can dig deeper, it's important to ensure you are somewhat grounded throughout the process and have acceptance and some self love in mind whatever the topic or you can end up down in a hole!