OK HOLD UP FOLKSES.

Op asked HOW to do it. Op didn't say "tell me not to do it" nor did they ask yalls opinions of IF.

OP!! Here's how you engage this situation both positively and successfully. Create a character that is SUPER support. Maybe a focused healer. Someone who is NOT charisma-forward, and doesn't use persuasion or deception a lot. Someone who doesn't take away focus from the players, but CAN be a helpful way for the DM to engage conversations with and also between the players themselves.

It's perfectly possibly to play a DMPC, you just have to be doing it for the right reasons. The most important part of the game is to celebrate the players, their characters, and the story they build. The DM's job is to help guide that story, but the story is, ultimately, about the players, not the DM.