Custody Question

My ex-wife and I divorced around two years ago. I was against it, but obviously it takes two to tango.

We live in different states, but it's coming time for our four year old to be enrolled in kindergarten. Currently, we swap every week. I get him for seven days, and she gets him for seven days. We are at odds where he should go to school. I can't move out there (PA), and she claims she can't move out here (NJ).

She suggested that she enrolls our son in PA, and I would only be able to see him every other weekend. I am not at all okay with seeing my son four days a month.

Is her proposition legitimate? I feel like it's incredibly one-sided. Am I wrong for freaking out that I will virtually lose all time I have with my son?

EDIT: I will definitely seek out a lawyer here. I'm just sick with the flu currently.