Trazodone is an antidepressant, though -- specifically, an SSRI. Too much of an antidepressant (especially SSRIs) can trigger or exacerbate mania. I'm not pretending to be a doctor, but I think it is a bad idea to keep taking double your Trazodone dose without talking to your doctor first. There are other options available, from benzos to antipsychotics like seroquel, that can be more effective and less likely to trigger mania. There are also sleep aids like OTC melatonin or even Rx Ambien.

I'm not trying to be an @ss, because I know you're struggling, but you may be making things a lot worse than they need to be and I think it needs to be said.