feedback as a crossword setter: published newspaper crosswords have rules around where you can have unchecked squares (where "checked" means "the same letter appears in two different words"). the most basic rule for new york times style american crosswords is "zero unchecked squares", and for british style blocked crosswords it is "no word should have two consecutive unchecked squares". not following either of those conventions gives the crosswords an amateurish feel, and also contributes to the "feels way too hard" feedback some other people have left.

Thank you, I'll look into implementing those rules.