Why did my plane descend nose down in an unusually steep dive?

I was on a flight recently and the plane started to descend normally etc. However one cabin crew member randomly announced “remember if we have an emergency landing please leave all your belongings behind”. I know this is said on auto announcement but I have never herd it said on a descent.

Anyway, suddenly the plane was going down nose down, controlled but lots of stuff rolled to the front. Several people were looking scared and I really thought/ knew it should not be nose down! This lasted about 1 minute and it then leveled out and landed fairly normally.

If that announcement wasn’t made I could tell myself it was one of those things but cabin crew never let on and now I can’t fly again but actually need to! I really thought we were crashing. Aircraft sounded normal but when it was nose down it was like the engines had gone really hushed.

I checked flightradar24 after we landed and there was a brief message flashed up that our flight was alerted by such and such a flight.. we landed at Newquay. The flight number was FR2954 on 12 Sep 2021 (ALC – NQY 03:40).

Can anyone say why this happened? I’m still shaken as I was always a terrible flyer. Something went on with that flight. I fly about 8 times a year and that has never happened! Why was the announcement made and why did the plane descend nose down?