There are three different things here though. Some men say they're after a committed relationship and lie about it. Some say they're just looking for something short term, no long term commitment because they're a nomad (or whatever) and some say they're after a committed relationship - but that doesn't mean they'll find happiness with any person who's also after the same thing.
I want a relationship, I say so on my profile - but I've broken things off with women before when it's become clear that I didn't want a relationship with them. I'd rather meet someone else who ticks more of my boxes. They may think, after the fact, that I was just looking for a fling and pretending I wanted a few fun weeks whilst lying about wanting a relationship, but it just took a few weeks to find out that that person wasn't for me.
The nomad thing dancemom - he's being honest with you. This will end after a while, when he decides to move on. Maybe next week, maybe next year. Is that something you're willing to accept? If not, then I'd call it off now.
There's an old saying, when a man tells you who he is, listen to him. Don't let your own wants and needs blind you to what he's telling you.