Seroquel is a anti-psychotic that failed in its original purpose to relieve psychosis, bipolar, schizophrenia etc. So of course what do drug companies do when they have a failure on their hands? They look at the side effects, and if one happens to be sleepiness, fatigue, they market it as an sleep medication.
Nobody knows what the long-term effects of this drug class are. It has some effect on the brain that's for sure; trouble is nobody knows quite what. The sister drug Abilify, also a anti-psychotic, is marketed as an "anti-depressant" and sleep med. You may have seen the huge marketing ads on TV. Of course, these supposedly don't cause dependency. Nancy Regean evidently got to some people, so Seroquel/Abilify are now "better" and "safe" and very heavily prescribed.
You might be better off with something in the benzodiazopine family. Because burning, buzzing in the brain doesn't sound like it should be taken too lightly. It wouldn't surprise me if it did have something do with the Seroquel. There has been a lot of overhype, I'm afraid, about benzos causing addiction, dependency, etc. Be assured, they are not the same as pain killers that respect. There's the occasional horror story, about a patient seeing purple unicorns for several days, but that is also the case with the "safe" ant-psychotics" and "ant-convulsants" which also have been repurposed.