My mom was on Seroquel for a while, and I did a ton of research and talked to her doctors and local pharmacists about it.
From what you've described, it sounds like withdrawal symptoms. Even though some doctors might say it isn't addictive, the body can become dependent on it, even in low doses. When you stop taking it, your brain has to re-regulate itself, and that can cause a variety of strange symptoms.

Everyone reacts differently, but it is very common for symptoms to show up a week or two after quitting. The "stoned" feeling, the internal body buzz, even the bitter taste could be all signs of withdrawal.

As for how long it lasts, that's really tough to say. For some people, it's a few weeks, for others, it can be a couple of months. The good news is that it almost always gets better with time.

Just be patient and try to manage anxiety. I know it is easier said than done, but the stress can make the symptoms feel worse. If it bothers you and you can not wait for it to go away, you can always talk to a different doctor, who has more experience with this kind of thing.
Hope I helped a little bit, let me know when you are better.