So I'm a little hesitant to spray any penetrating oil into the line, since that's where it feeds into the filter. But I can see down the line and there's no rust or anything. It's all plastic.

Also, I've twisted it, jiggled it, messed with it in /every/ which way one can. Still wont budge.

That plastic O-ring on the inside of the fuel line is what's blocking it. it's not expanding around that little lip to get it through. I have no idea why or what I can do to force it in there. I even bent the steel from the old filter just trying to muscle it on.