I spent some time exactly where you are. I figured out that I was basically living within the context of need, not of excitement or purpose. You can read more about it here: Why does purpose matter?
Since my overall life context was one fo survival/need, and my needs were already being met at home, why the hell would I wanna go anywhere else? Thus, zero motivation like you're saying.
The way I got around that, though, is to find goals that really interest me and challenge me and totally ignore survival-based thinking. I also basically sidestepped finding a purpose (and I can figure it out whenever later), and just go with goals that are interesting and challenging. Big, hair audacious goals as Steve says. You may have to give yourself permission to really want something and desire something and allow it to pull you out of your comfort zone, even though wanting something and not having it can be uncomfortable. Look up his "Cultivating Burning Desire" article. You can also spend more time reading about those things you're interested in, watching movies/shows about 'em to stoke your desire. Like, you wanna travel, go check out some travel guides, youtube travel videos of places you wanna go to, etc.
BTW, these goals that you choose can be small ones and ones that don't seem to matter much. For example, read three books this week, or five or whatever would be a stretch for, a bit of a challenge. Just set goals, any goals right now. you can figure out what you really want later, just start setting goals and get used to that.
Also, recognize that unless you do something now, you may well be stuck like this for the rest of your life. It'll always be upto you. Nobody's gonna come in and fix your life, not Steve, not nobody. You're on your own in many ways. Good luck.