Not sure what occurred here

I have sensed and now can communicate with someone who can only be part of my original personality Toni. It feels like piece of Toni dissociated from the rest of Toni, and seeks to develop enough to fully combine with Toni. I know it is different from the other dissociative states being merely a modes / versions of me, it really feels like something Toni has been missing. Can you help me figure out what occurred here?

It sounds like you have become aware of an alter who you didn't know about before. That's a pretty common occurrence with DID/OSDD.

Current theory doesn't support the existence of an "original" personality, since we're all born with various self-states, and these gradually unify over the first few years unless the process is interrupted by chronic or repetitive trauma. But this could certainly be an alter who was present since very early in your childhood.

It's also common for some alters to be very similar and connected, and others to be very different and less connected to the others. That's one of the reasons people's perspective of whether they have DID or OSDD can shift, depending on which alter's views are prominent.

I hope you're able to get to know them better and continue to learn more about what's happening.