Re: What went wrong while sailing downwind?
Do you have a means of reefing the mainsail. If yes, then you should have done that as soon as you realised the wind had risen beyond your comfort level.
One of the best pieces of advice I got early in my sailing days was " Reef the first time you think about it "
Like wise if you have a smaller jib change to that too.
It is always much easier to add sail area that to reduce it.