Yes you could go to jail for having sex with her. Getting her pregnant would only make matters worse if that is at all possible.

The only way to fix this is to hire a lawyer. It will depend on the evidence.

No it is not illegal. Happens all the time.

You will need to seek a court order for custody.

So you want to hire a lawyer, pay filing fees and wait months for a court date over a meal? Sure, go for it.

A 9 year old? Hopefully his parents have hired a good lawyer.

Whether one of us says you will likely lose or likely win is pretty useless given that we know nothing about the situation.

Whether one of us says 62% or 26% it doesn't matter. Get the best attorney you can afford.

You cannot sue for an allergic reaction. Hope you get better.

IMO you can answer that you have never been convicted.