I wouldn't take anxiolytics/antidepressants. Atypical antipsychotics work. Quetiapine is very antihistaminergic and is metabolised/effective quickly. Low doses are relatively speaking more antihistaminergic than antidopaminergic and serotonergic. All these characteristics are good. But in the meantime, if it's easier to have it prescribed by your GP, you may take (just) a antihistamine, but you need a high dosage. Probably at least four times that of people having insomnia but not mania.

Amphetamines I wouldn't use either. Do you only have or notice concentration problems at work or always? I ask, because you must have an abnormal ability to focus, doing software development. Maybe you can switch tasks more often? That might help. Do you use a lean type of development process at your company? Maybe ask whether you could work on more than one issue/task at a time.