I would get a lawyer. SC has very specific guideslines as far as child support. You can find it on the web. If you plead guilty to adultery you can be legally divorced in 90 days-but you will most likely have to pay alimony. The amount of the child support and alimony may be equal to the amount you have been paying to support her.
It would be reasonable for her to get a job. A judge may give her a specific amount of time to do so.
You set yourself up for a fight by living under the conditions that you did. The fact that you have demonstrated that you are willing and able to pay the amount you have been paying-is going to hurt you.
You better consult an attorney and before you move forward with any new relationships.
I wish you the best.
-------------------- Message for my ex "I think you know by now, I'm not the person I used to be"