Me at the stronghold:

Correct!

Me entering the stronghold, seeing that there is an amythest geode in it, ignoring it, then realizing that the portal was in the geode an hour and some internal screaming later

I struggled with this for years, but then I learned a useful trick: only go through backward doors and then you get nearer to portal room

YEP

If this is true, then follow the left side of the wall. It works

Instead of looking for an exit you're looking for an entrance

i mean they are both portals to different reality soooooo.....

Strongrooms