I used to have a pretty terrible sugar addiction, but I'd say it's well and truly beaten. And it's amazing what a physical/chemical addiction it is.
For me, the only think that worked was cold turkey. (And it doesn't have to be "I can never again have sugar." I can eat it now in small amounts without becoming re-addicted (though I occasionally suffer mild withdrawal after too much indulgence,), without NEEDING to eat it. I can easily say no, and sometimes I can say "no more") It takes a huge amount of willpower to stop cold turkey, and it also takes setting yourself up for success. You need to throw out (or donate, or give to your colleagues or in some way or another remove from your house, car, office, purse, etc, from your possession) any and all sweets. I was able to quit while still having a bag of sugar in my house for DP to make kombucha with, and other baking supplies, because I never bake sweet things except birthday cakes on birthdays. The goal of removing sugar is to make in inconvenient to get your fix, and give you time to eat something else and remember that you don't want to eat sugar, and let your willpower kick in. For some people, who love to just whip up a batch of cookies, having baking ingredients in the house is not safe. For me, since I haven't made cookies in years and years, because I just never even think to, or have the ingredients on hand, or really want to (I'm not really a baker), it was ok.
Some people also try to not eat fruit or natural sweeteners in this period, but I found that I was fine with just cutting out refined sweeteners. I stopped eating brown sugar, white sugar, corn syrup and it's derivatives, artificial sweeteners, and any other "chemical sweeteners". I continued to use maple syrup, honey, palm sugar, black strap molasses, and fresh fruit. I didn't restrict my consumption of natural sweeteners, which as first was high, but as I recovered from addiction, decreased to very infrequent.
You will feel terrible for at least the first week or so, as your body goes through withdrawal, and crave sugar so much worse than you did before. But after a week or so, it starts to get better. It took about a year before eating dessert two days in row would not cause me to go through a withdrawal again, but never as bad as the first. I started having sugar on special occaisions like birthdays (family birthdays, not for instance, your kids friends birthdays every few weeks, but birthdays a couple times a year) after about a month or two, and found that dessert on one day (but not two) didn't cause withdrawal again.
I recommend when the really strong cravings hit, that you eat a little peanut butter mixed with coconut oil and raisins or other dried unsweetened fruit. It tastes sweet, like a dessert, without actually having very much sugar at all, but it helps meet the need. That and cream and fruit helped me a lot, and when I first started, I had one or the other every night after dinner. (Not whipped cream, because that you eat and miss the sugar, but unwhipped cream is rich and sweet.
In my experience, sugar cravings are a combination of three things: a physical, emotional and chemical addiction, a need for protein, and a need for healthy fats (coconut oil, olive oil, grass-fed butter, fatty fish, etc.) Lean protein doesn't help with sugar cravings but rich protein with healthy fats does. That's why peanut butter and coconut oil together help.
One of the biggest helps for me was getting "caught up" on my fats. I had eaten an extremely lean diet all my life, and had desperately craved fats. When I started cutting out sugar, and eating my fill of healthy nutrient dense fats, I found it helped with the sugar cravings. As my body slowed it's fat cravings and got enough fat, the sugar cravings also slowed. That process for the most part took about a year (wrt sugar. wrt fat, I'm still craving it somewhat, though now, 2 years later, my fat cravings/consumption are returning to a more normal consumption.)
I hope that helps. I'm happy to answer any questions I can about my expierience recovering from sugar addiction. It is so worth it. I feel so much better, and am so much healthier. I still enjoy sweets now and then, but I can eat them without craving them, and want less of them, and naturally sweet foods like good fresh carrots, seasonal fruit, and honey taste incredibly sweet to me, because my tastebuds are no longer deadened by refined sweetners. I still sometimes crave something sweet on my period, but some honeyed toast, or seasonal fruit is enough.