Well, seroquel definitely can cause weight gain and metabolic changes. I guess it depends on the cost-benefit of the side effects of the drugs versus the reasons you were put on seroquel in the first place. That requires some insight into why you started it, and a reasoning for different scenarios. I was on seroquel (up to ~150-200) as an adjunct in depression when I had really bad insomnia, and while it did the trick for sleep my depression did not improve significantly. A little bit of sleep disruption when quitting but I had started another medication for depression which ended up improving my sleep more.
I have a friend with depression and bipolar II who struggled with weight gain from seroquel (went from underweight and not eating to overweight), and definitely had the 'not sleeping a few days' experience whenever she went down on her dose (400 to 300 or 200) or tried to come off. Overall, the balance for her was to switch to another antipsychotic. Notably however, she had cold-turkeyed from 400 and was doing 'well' 'naturally'(hypomanic), and rapidly declined about a month later, leading to a hospitalization. She is now on aripiprazole and some antidepressants.
It can be useful, and may even be essentially necessary, to talk to a provider about coming off a medication, depending on the condition that you started the medication. Especially if it is a condition that can lead to distorted thinking (such as my depression) and warped perspectives, where great caution should be taken. To be fair though, not all providers are particularly accessible. Writing down the relative costs and benefits, and giving the situation some thought and an outside perspective, can be helpful. It may not be enough to guess how things will work out as you see them now. 'What would I think and do if I were thinking in a particular manner, and what will I do about it', may be applicable. It can be easy to measure the benefits of not having some side effects right away, but the costs can be trickier to project. Have a solid and tangible plan if things go south, and don't believe a rosy scenario, especially if you have a history.
Best of luck!