If introverted isn't something that you believe you truly are, then maybe you aren't? Trauma plays out in ways that it does for many. Think of your neural pathways cross communicating because of them being blocked by stress of memory. As though your brain is doing this to prevent the memories from flooding all at once, yet because the brain doesn't just house memories, it also affects how your body physically works, speech and all, this is what's happening..for now, until the flooding subsides from the trauma counseling. Best analogy that I can think of.
If a social butterfly was you, you'll perhaps get there as you get better?