It sounds like it means that you dissociate when triggered back to the trauma, like a war vet who tries to watch a war movie, but ends up dazed, foggy minded, entranced, triggered from watching a battle scene.

I can see where you are getting at on the RP thing. Sometimes when things happen to us that we can't explain, we attempt to describe it by only what we know, like you called it role playing, some others might call it acting, others possession, and so on. What you are a actually going through though, I couldn't tell you, that would be a therapists job.

When actors act, their characters become their alter ego- a second identity (be it just for a short while), which isn't the same as having alters- like Stefani Joanne Angelina Germanotta....a.k.a. Lady Gaga.

When role playing, it is intentional (to act) to be the alter ego which one molds and creates, whereas having a dissociative alter present, their personal traits and preferences bleeds through without any input from the host.

Of course, acting like an other character can become natural- that's why they are called good actors. What you are describing I have no clue, only you can say.

Alters usually step in when the host dissociates due to a trigger to carry on being actively participating in their own special brand. Other times they can influence the host in a many other ways, like feelings of emotions that are overbearing, unusual, unfounded,...thoughts that are contrary to the line of thinking,...

They can also blend where their characteristics manifests just like how you described which is my cause for wonder. Not everybody dissociates, some are prone too.

So, if you are role playing, then you are just doing that like you said. It looks to like you've been doing it for so long that it's become natural, idk.

All this would have to be discussed and explored by you and your therapist, and I hope this helps some, just my two cents.