"I am waiting for Passover to arrive because then it will be possible to eat matzot."
Translation:אני מחכֶה שיגיע פסח כי אז יהיה אפשר לאכול מצות.
+1 התרגום שלי זהה אך לא התקבל
אני מחכה שפסח יגיע בגלל שיהיה אפשר לאכול מצות
This is a wrong rule enforced by misguided pedants. The construct "בגלל ש" is actually considered valid - see for example http://hebrew-academy.org.il/2010/10/14/%D7%91%D7%92%D7%9C%D7%9C-%D7%A9%D7%81%D6%B6/. This page (in Hebrew) explains that although this construct did not appear in ancient Hebrew, there is no reason not to accept it today. It is very commonly used in spoken Hebrew (and yes, people who use it have to endure with pedants trying to "correct" them, so perhaps for this reason alone you should avoid it, and prefer a synonym such as כי or a dozen others mentioned on that page.
And no one is waiting for that reason I assure you! Also you could buy matzot every day...
There is a custom not to eat מצה from ראש חודש ניסן until פסח. And there are people who enjoy מצה for its own sake. So during those two weeks this could totally make sense.