Okay .. Not laughing.. By your description, it seems as the lower portion of hitch (part with the locking handle) could be rotated to clear the gusset(the V thing)

To do this.

Hitch your truck to the trailer. but don't lock anything.  This is a safety precaution.

Then use the jack to raise the hitch off the truck's ball by 1/2 inch.

Then loosen the locking bolts that hold the lower portion in  the upper tube.  You will likely have to loosen the locking nut on the screws too.  Safety here... When you loosen the screws enough, the lower hitch will drop down.  It's heavy.  The truck will stop it from falling all the way out.

Rotate the lower hitch so the locking handle isn't blocked anymore.

Lower the trailer until the hitch is the same length it was previously, Then retighten the screws and lock nuts.

You should be able to use the hitch locking handle holding stud now.

Congratulate yourself on a good job!

Another tip:  Use some thread penetrant like WD-40 or rust-buster the night before on the locking screws and nuts.  After two years in the weather, those threads could be mighty stuck with rust.  You will need a very large wrench.  Maybe even a piece of pipe as a cheater bar.

Did this solve your problem?