I am wondering if I went cold turkey what would happen and how long would it last.
There are a lot of factors. It depends how long you have been taking it and how much you take.
Cold turkey would involve headaches, nausea (possibly being sick) sweating, shaking, cold and flu like symptoms and not sleeping.
Tapering would be better than going cold turkey
Cold turkey IMO is best and quickest way. I took codeine for about 10 years and went cold turkey 7-8 weeks ago and still clean with no cravings and no depression. Week 1 will be aches, restless legs, insomnia, loose bowls but they do fade away quickly then up to week 4 you will feel depressed with no energy or motivation but you just have to remember that it does get better and easier and I’m speak from experience it is totally worth it I feel a million times better than when I was taking codeine