Hi Cynthia, welcome to the forum!
Sertraline sure has a laundry list of discontinuation issues associated with it, as do most SSRIs. Anecdotally, I would say that SNRIs are very tough to discontinue, perhaps more so than SSRis, but that doesn't quitting either class of drug a cakewalk. The only AD I've ever found easy to discontinue was Wellbutrin; I was able to just stop taking it.
Are you quitting Sertraline with the aid of a doctor? I only ask because it helps to have someone monitor you for behaviour
changes. The benefit to a slow ween is that your brain is able to start moderating the neurotransmitters that it was previously counting on your ADs to moderate. Unfortunately, there seems to be a lag between the time when your ADs stop working, and your brain starts picking up the slack again, which is why, for some people, it's much safer to ween. Discontinuation is a complicated process, and I hope you're successful.
Things to watch out for are outbursts of anger, crying, despondency, and anxiety. Generally you can expect to deal with that stuff even when you're weening, but a cold-turkey discontinuation can allow that stuff to get out of control. Your list of supplements is a good one, so few people know about
CoQ10 especially, I'm glad you found it.
Don't sell yourself short. If your discontinuation gets intolerable, look at substituting the Sertraline with another AD with a long half-life. Perhaps Prozac. The upside is that weaning off something with a longer half-life is much gentler on your brain.
Hope you hang around! Lots of cool people here, and we're always ready to listen.
Take care, Cynthia.