That fell through, and I actually told him, yes, you can stay with me, but you will have to get a job and pay some rent. That was like, at least, a month and a half to two months ago. I finally gave him two weeks notice- find a job or you are out. Literally, with only a day or two left, he said he got the job.
Alright, I feel like I gotta talk about this. Do you know how the current job market and hiring processes tend to work? You're acting like a month and a half is a suspiciously long time to get a job and that your expectation was that he should've had something within a few weeks. However, the reality is he could've applied to that grocery store the very same day you first told him he needed a job and it took them at least a month to get back to him. Before I got my current job, I was in a slump and was applying to grocery store/fast food/etc tier places because I just needed anything to sustain myself while I continued to look for a job I actually wanted and sometimes I wouldn't hear back for months, sometimes not at all. And no, following up with places like that will not expedite the process. And he doesn't even have a GED! He's probably getting bumped to the back of the line the moment they look over his resume!
Wanting him to get a job isn't a big ask, but wanting him to get a job in such a time frame kinda is.
Any, "how's the job hunt going?" kinda thing you might've said was gonna be super demoralizing and the two week ultimatum is a bigger signal for him to just give up. I know you didn't mean it to be that way, but my read on what you've said just seems like you were putting him in a place where he is less likely to get and stick to a job, especially because all the jobs he's looking at are probably going to suck. And if he ever finds out you tried to check up on him, whether he actually has the job or not, he's gonna start hiding way more shit from you.
Honestly, if him getting a job is such a high priority thing for you to have happen, I think you should be pushing more for him to start doing some weekly volunteer work or try for a GED or any other part time goal that would that would make him productive, make him more marketable in the job market, and not fully interfere with his job search.
If he's in a fucking hole, which it sound like he is, telling him to get out of the hole is just gonna make it deeper and it's not gonna solve your issues.