Ughh please help

So I’ve been single for months, yes focusing on myself and loving myself and all that good stuff. But this voice in my head keeps telling me I’m in my mid 20s and want kids someday so I better start going on some dates. I just have no interest in any of these guys I’ve tried to talk to. There was this one guy I thought could have potential, he wanted to fuck so I did bc I was horny but sex sucks without emotional connection for me and after some more dates with him I realize I’m just not into him and will never be but now he wants to keep seeing me but I have to tell him I’m done basically, idk how to tell him? he’s so freaking nice and I don’t know how to do this.