If my ex-boyfriend and I are both on the title of our truck, if he keeps it I'll be left with nothing, do I have any legal safety net here?

My boyfriend and I are both on the title to the truck. We are breaking up. It's worth more than we paid for it. He refuses to sell it and split the money. He wants to keep the truck but can't afford to pay me half of what it's worth. He said he might consider giving me part of what we paid for it. The truck is really the only thing we have worth any money. If he keeps it I'll be left with nothing.