If my ex-wife has full(sole) custody for my daughters and does not let me see my daughters at all. I am now remarried and have 3 more children , but she keeps calling and asking for my address what can I do? Do I still need to pay child support even if she has full custody & won't let me see my kids?

Yes, of course child support and visits are two separate things.

To owe child support she went to court and got a court order for support. To get visits you go to court and get a court order for visits. If she does not let you visit then you take her to court for contempt or the child visit order

Child support and visitation are two different things, as FrChuck explained. Go to Court and get visitation.