I have had ambien, trazodone, and now lunesta (eszopiclone). i took 2 mg of luniest but it's not working; can i take 5 mg of ambien?

No: Stop it, please. Adding more sleeping agents without consulting your prescribing dr is always wrong. Rather go back to the office and ask what other measures and meds can be tried, give your dr a fair chance to fix it please.

Insomnia treatment: No. Your question is basically the first slide of a talk i gave few years ago as representation of a wrong treatment. Most "just insomnia s" are treated with cognitive behavioral therapy not medicine. Medicine decreases your sleep efficacy and makes you worse long term. But a sleep doctor has to make sure you have no co-morbid interinsic sleep condition like sleep apnea etc.

Total agreement: You are in a pattern destined to, in the end, provide significant sleep disruption. Sleep medication per se, in my experience, invariably develops tolerance and increasing insomnia. An overnight sleep study is needed in the near future, and the recommendations of my superlative colleagues should be heeded. Wonder if you need to find a sleep specialist to get involved in stabilizing all of this.