Children being withheld from father by mother

Mother and father have split due mother's hidden affair. Mother took children and went to live with her mother in Pekin, IL. Mother and father r still yet to file for divorce. Due to mother's bad spending and ripping father off of everything. So child custody has no legal agreement. Mother and father came to previous verbal agreement for father seeing the children. Until father had seizure break through his meds back in February. Mother forced father to start seeing the children under supervision. Father went to doctor and is back under control. Doctor also approves him to watch the children alone. Has doctor's note to prove it. Mother won't accept doctor's approval. Father has tried several times to have the children on his own or restart the verbal agreement. But has been denied his rights. Has been denied his rights at holidays and his daughter's birthday. He has proof of it. There r 2 children. One boy age 4 and one girl age 2. Father has not seen either since July and not on a regular basis since May. Today the phone even gets hung up on the father when he calls to talk to them. Father notices a possible scam by mother based upon what happened with his previous daughter. Previous daughter was kept away from birth to age one. Learned next boyfriend as dad. Father ends up signing his rights away for the good of the child. Previous mother sues father for back child support. Father today sees same thing being performed by current mother/wife. Current mother was around when previous mother did what she did. Current mother's new boyfriend does live with mother at her mother's house. Father is concerned 2yr old daughter will learn new boyfriend as dad. Father is also worried she will do like the other mother and sue him for back child support. Just to get money. And father will have unfairly not gotten to see the children. Father wants this divorce and child custody battle to happen and be over. But over he wants to be able to see his kids and see them unsupervised. Since it has not been ruled by the courts that he have supervised visitation. Father wants to reunite with his kids and be a part of their lives once again.