What to do if my live-in boyfriend and I recently bought a car in his name only but the relationship just ended and I drove the car out of state?

If your name is not on the car note or the financing agreement and you were not married, then your only obligation is to return the car to him as in good of condition as you received it.  You are not required to get it fancy storage or purchase insurance.  As the title holder, those are his duties.  You need to find someone to go with you and return the car with this person as a witness.  You seem a bit nervous about being around him, so a witness can provide protection from any unwelcome events.  The witness can also help verify and serve as proof that you returned the car, and in good condition (to help avoid any claims of theft or criminal mischief at a later date.)  You can return it to him at his residence, employment, or any other location he directs you to take it --and that you can mutually agree upon.  This location could be the dealer, a close relative, or a close friend-- but again, take a witness with you.  If he just refuses to talk to you in order to arrange for the return or he's unreasonable about how to return the vehicle, then send a certified letter directing him when and where to retrieve his vehicle-- and you just set the terms of pick-up.  If he still refuses to pick it up, call the bank and let them know where the car is once it's had time to fall into default.  They really don't have right to operate the vehicle until he defaults on the car note.

As an extra precaution, take pictures of the car with a camera that has a time and date stamp.  This will give you additional verification of the condition of the car before you return in.  You also raised a concern about damage to the car while this is going on.  While you are arranging return, drive the car as little as possible--- preferrably not at all.  This will minimize the risk to you and the car.