Potential Custody issues

location: Ohio Hi I am wanting to post just for some general guidance I suppose. I am 30(M) have 2 children with my girlfriend 26(F) both toddlers. We’ve recently broken up and now I’m worried she will try to keep me completely out of the kids lives. Is there anything I can do to prevent that? What recourse do I have if any? I like to think I’m a decent father to my children, I don’t drink or do drugs. I have a full time job that pays decent, for the area. Really just in a rough spot and I’m not sure what to do.