Hard to say for sure, what happened. Certainly, you don't want to heave-to with anything more than 100 % since the sail will chafe on the spreaders or shrouds.
Perhaps it was too much sail for the wind.
I don't usually ease into the tack, I just roll up the furler
to about 90% and then do a quick tack, leaving the jib
. Once I'm through the wind, I let the traveler out all the way and turn the wheel to windward..( Rudder to Windward). Sometimes I may have to ease the main a little more..and adjust the rudder if I'm in a current..
Did you remember to put the helm over?
Every boat will behave a little differently.
I do this all the time to take a reef, shake one out, have lunch, catch fish...etc.
I would just continue to practice in varying wind conditions and sail shapes, you'll find the sweet spot eventually.