You should do what you think is best. Doctors may advice you and it might be great advice, but it's always just experimenting. Just purely from that perspective, adding meds only makes it worse.

What you knew might still be correct. It's hard to tell with effectively four antidepressants (as quetiapine is an atypical antipsychotic, being antidepressive). Of course, it might've been wrong, but by no means is it certain, unless you experienced problems before the use of antidepressants. No matter how many doctors you visit, you can never be certain, unless you experiment, assume that it may be med-induced..

It does depend on how you define BP, of course, but the newest DSM has a separate category for med-induced BP. Again, it might be "just" BP, but you may want to make sure.