Discuss family topics/issues, and give and receive encouragement here.
Then you will know the truth, and the truth will set you free.
And now these three remain; faith, hope and love. But the greatest of these is love.
1 Cor. 13:13
Give peas a chance !
It is not judging to point out the obvious. You are living in sin, to a man you are not married to. Technically, he has obligations to support your son, as he is his son, too! But really, no obligations to you or your daughter.
You placed a lot of faith in "signs" that God was fixing the relationship, even thought it was going south all the time. Those were not signs, they were a man who wasn't willing to give up the comforts you gave him. Now, he is done, for whatever reason, time to get a real life.
Don't get involved with and have children with men you are not married to. The world says differently, I know! Maybe you didn't even realize it was against God's plan and purpose that a man and woman should be married, before they sleep together. Now you are forewarned, so do not continue to sin.
Tell this man it is over. Tell him you want support for your son, and you will take him to court if necessary. You might also tell him, if he gets saved, you will work on your relationship, but from separate homes. See if he changes. If he is truly saved, God will change him. If his using and abusing continue, that means he is not saved.
The Bible tells us not to be unequally yoked. That means, you should not marry this man, nor any other, if they are not born again Christians. I am not talking baptized as a baby! I am talking fully committed to God - regardless of the church or religious background.
As for you, I hope you will realize we care, and we know that what God says in the Bible works! You have made some bad mistakes, but God will forgive you, if you confess and tell him how you have gone astray. And he loves you, and will help you through this difficult time.
"And He has said to me, “My grace is sufficient for you, for power is perfected in weakness.” Most gladly, therefore, I will rather boast about my weaknesses, so that the power of Christ may dwell in me." 2 Cor. 12:9 NASB