What are replacement drugs for Seroquel?

I would say all potential side effects of Antipsychotics are serious after being on Seroquel and Zyprexa (Olanzapine) for over 25 years for bipolar disorder. As you mention Lithium was greatly prescribed to act as a mood stabilizer, and it´s possible side effects were also serious.
After being on many meds I would have to say that all of them carry high potential side effects.
As you probably are aware everyone reacts differently to medications, having said that there are quite a few alternatives to Quetiapine that with the help of your Psychiatrist you may find one that suits you best, it is, as you know trial an error, until you find the right one that works for you, but again, they all carry serious possible side effects.

List of antipsychotics
Atypical
Miscellaneous antipsychotic agents
Phenothiazine antipsychotics
Thioxanthenes

https://www.drugs.com/drug-class/antipsychotics.html

Hi, Amiodezky!
Lithium is still prescribed frequently especially for patients who don't respond well to other psychotropic medications.
Are you taking a mood stabilizer like Lamictal, Trileptal, or Depakote?
I'm taking Seroquel and Vraylar which is an antipsychotic that treats schizophrenia and Bipolar disorders. I've had no problems with either medication and they work well for me. Seroquel made me sleepy at first but that resolved after a couple of weeks.
There are other drugs that might help you so it would be a good idea to discuss this with your doctor/psychiatrist.