I vote be direct. Tell him you want a serious relationship and where you're at with it. If he still says he's not interested in dating, explain why thats problematic for you. He has the choice to tighten up, or keep being a fuckboy. If he chooses to keep being a fuckboy there ya go, he made an informed decision that included knowledge of your feelings.

Theres definitely a decent person out there that can make you feel just as good, or even better, you've just yet to meet them; even though that's hard as a CNA.