@elena I've been self-hosting & sysadmin-ning for… I don't know… more than 30 years now. Both for fun & as for my day job. Please believe me that running head-first into such walls happens to us veterans, too, including days in which I don't seem to be able to make any progress whatsoever.
Frustrating as heck when it happens. I get it. On the other hand, when you do figure these things out, sometimes a day later, sometimes half a year later, it can be so rewarding and incredibly fun. And best of all: you learn a lot, even (especially?) in failing! 'cause you still look up a lot of documentation, get to know logs, inner workings of programs/OS/protocols/APIs, or just by researching alternatives.
Keep working on it! This is a fantastic journey, with a lot of fun to be had.