To reduce dissociation you can use things that produce strong and positive sensations such as strong smells when the dissociation happens (this is called “grounding” and lots of people online post ideas for grounding for trauma).
Some things that work for some patients include essential oils and stress balls.
Looking at comforting pictures of the place where you are with writing on them that says things like “I am safe” and “I am in (location where you are)” that you can repeat to yourself when you dissociate can also help.