My Son Needs To Come Home From His Father, But Not Sure What I Can Do Legally Without Tying It Up In Court And Prolonging His Suffering

Location: Nevada

ETA: a couple questions to emphasize--the stipulation changing custody to dad was filed in Nevada where I live and where divorce took place. Does any future action now require a lawyer and legal action in dad's state?

Many are suggesting I just take him or give him a ticket to leave. I'm concerned this could be contempt or kidnapping. Isn't it?

Original:

I've had primary physical custody and joint legal custody of my son since he was 2. He is now 16 and wanted to live with his dad to have access to the university his step mom works at which is a well known top notch university for astrophysics. He made the decision in a mature and future focused way. His dad lives back east. So his dad and I worked out an amended custody agreement for him to go out there. That was peacefully done via mutual agreement. I made certain in this custody agreement there was verbiage saying he can come back if he decides to.

He moved out mid July. By end of August he was experiencing a mental health crisis. Early September he's hospitalized for suicidality. At this point my son is begging to come home. And I'm trying to make that happen once again in a peaceful manner. The quarter is ending at school soon and I've been pressing to have him come out then. Dad is now saying he has to talk to his lawyer, etc etc.

He's been making my son miserable. Denying him access to a cell phone I pay for on the premise of bed time but the phone has been out of my son's hands for days. He has taken all my son's coping mechanisms away such as his record player and his piano keyboard. Because he might "harm himself" though my son has never exhibit self harm behavior. Only ideation. Most of this information I'm getting through the sisters (who are in their 20s)

Today my son sent me a screen shot of a bunch of texts his dad sent him. This won't allow me to post it but here are some examples:

"BACK TO THAT FUCKING LOSER SHITHOLE STATE NEVADA!!!"

"you can have your old phone back from your mom since she keeps bugging the fuck out of me that you have that... I'm taking this new phone back. You won't deserve it.".

There's other things but this one of the few things I have screen shots of.

The thought to do an ex parte motion to hasten my son coming out here has entered my mind but my budget isn't great and last time we had something come up where one was filed for emergency amendment to custody (he had a drunk woman around the kids and domestic violence was involved) they didn't side with me and it wasted thousands. I also don't want to end up having his dad tie this up unnecessarily to drag it out.

There has been no physical abuse. There has been verbal abuse as above, invasion of privacy, restricting his access to support people but I think most of that is unenforceable absent a major event.

What are my options and benefits/drawbacks?