[Yakin]

Yeah sounds like you just had either your drag way to tight or just really old line or a combo of both!!
Sorry to hear about your losses.
When it comes to my drag and I am trolling I will have my drag set half way down from where I would fight a fish.
I normally use on my Shimano Baitrunner I have 20 strait Izor mono.
on my jig masters I am running 50 braid with 3'-6' stop shot 30 Izor,
and 10+ up on each on another jig master!
You will hear many debates on this subject once people notice it.
So you will have many many MANY opinions to pick from by the end of the day more then likely!!!
Like I say:
Opinions are like A**wholes.
Everyone has one and some are better then others.
All just opinions and it is what works for you.