You may want to get some legal help to know your rights and give you some grounding on what options you have. Not to use at the moment, but to know where you stand. I smell a rat when you say she is the one who just decided for no reason you aren't fit to be with the kids alone. Could she be setting you up to be seen as an uncaring father who abandoned the kids? I wouldn't let this continue for long and be sure to document every instance you attempt to be with your kids and her blocking it or controlling the access. Courts love documentation to backup what you say. You have as much right to be with them alone as she does unless there is something else going on I don't know.
Me:49 W:45 M:19 T:22 EA confirmed and ended 8/2014 S:19,17 D:9,5