Re: The baby is mine and he does not know
OK I will try and keep it simple:
You need to recognise that the woman you are sleeping with is a vile person. Not good for you, her current bf and probably not even her ex. She is a liar and a cheat and will manipulate people at will.
Having recognised this, you need to understand that you have been a bad person in continuing the affair even after you found out about her bf who is a good man to take care of her child as if it was his. This is not how a decent person would behave.
Having recognised each of the above and accepted it, you must do separate things about each of the above.
You must break off your relationship with the woman whether the baby is yours or not. This is not saying that you should walk away from the baby. You should be willing and able to co-parent with her if the baby is yours. Else dump her and explain why - that the both of you were behaving badly and that you do not think she is a good person.
You must come clean with the bf even if there was no baby. Explain that his "gf" has been cheating on him for some time now (with you). Apologise sincerely for your part in this. Then tell him about the baby possibly being yours. And help him even if he hurls abuse at you.
Hope that is clear ...
This is my quest, to follow that star
No matter how hopeless, no matter how far
To fight for the right, without question or pause
To be willing to march into Hell, for a Heavenly cause