but it's not practical. What am I doing wrong?


I think this quote is in the wrong order, because the first phrase is
the answer to the question.

You're playing with the edge of practicality, even if the technical
side is still ok (meaning Excel didn't just chop off some of the
text). At some point, you start running into not-foreseen issues. And
you may find workarounds like Dave suggested, you'll have to decide
what is practical.

Eventually, you'll likely either have to spread it to other cells or
leave Excel and open a program made for so much text. Word comes to
mind.