There are too many timeline branches from that one incursion to cover all the bases here. Does someone with my name exist (alternative sperm / egg theory)? Do they live in the same house? Do I get caught and arrested either way? How soon do I realise what's happened?
I mean I probably realise a lot sooner than the average person because I've consumed a lot of sci-fi and am well aware of It's a Wonderful Life, but it doesn't really help.
My parents probably live in the same place. I'd go there for help if I hadn't figured it out yet. Maybe if I had. I don't know whether they would help for sure though.
My father might think I'm actually a descendent of one of his parents' relatives. My mother would definitely see the resemblance. Maybe I also look like my "replacement". That would be traumatic and confusing for all concerned though.
Imagine getting a DNA test done to prove it. That's a long way off and/or unlikely , but it would conclusively prove I'm their kid. There'd be hospital mix-up investigations. It wouldn't be the first time there have been twins. Now I must be a long lost fraternal twin of another person who has my name.
If they have no child of a similar age, that just raises even more questions. Did they collectively lose their minds and abandon a child at some point?
But that's distant speculation. Maybe they tell me to get lost. Maybe I don't go there in the first place.
If I do realise what's happened sooner rather than later, maybe I leave my parents alone. I'd probably go to a local hospital and lurk around the cafe and shop until I get help, get my head together with a better plan, or get arrested. I need medication anyway, not that I can prove that. I assume drug names are the same.
I'd probably have to take each moment as I find it and act accordingly. As to how I'd act, that's very hard to say until it's actually happening.