Hi Spikes!
This is such a common problem for most of us, if not all.
I am sorry you are having to make a new choice, but maybe it will benefit you more than you know. I tell myself this when I have had to change things up yet again!
Is there any chance of you having access to the (more expensive) meds you have mentioned in the beginning of your post?
I have had a problem, too, when trying those meds. It has been very expensive for me , and in the longer term, just not possible.
If the meds you have used, do work as you say, why not use them? It sounds like you might be favoring haloperidol (Haldol)?
I know akathisia is so very uncomfortable. Do you truly get enough relief with cogentin?
I know many of us gain weight on Seroquel. I am wondering if you might be able to find a lifestyle which allows you to maintain your current weight while using Seroquel? It might require a change in diet and some additional exercise. I understand it also makes you tired.

I wonder if added exercise might counteract some of the sleepiness?
One time I had to take Seroquel, I did quite well and even lost weight on it. Yet, another time, not so much. It might depend upon my underlying mood?

I do think maintaining weight might be a possibility if some measures are immediately put into place. I think this is a bit different for everyone and can very in each course of Seroquel.
I understand some people use a med called: Metformin to help with weight issues related to some of these meds. I am ignorant to this, in that I have not used this med. I hope someone with experiences with this med might come along and offer more info.
I am not sure how much these meds effect your glucose metabolism; they do cause issues for many. Many become pre-diabetic or diabetic. If this might be the case for you, here is a resource you might find helpful. Metformin is mentioned in this article.
Experts recommend two-pronged approach to treating prediabetes
I hope you find the most helpful med with the least bothersome side-effects.