Could i drink zzzquil every night?

Only for a limited: period, read the labels and cautions, the least is that you would develop tolerance after sometime, you would need a higher dose dose to get the same effect, needing it every night for whatever reason indicates ongoing problem which needs to be professionally addressed, good luck

For short periods : Yes, but this isn't something meant to be taken every night for prolonged periods of time. If you are having that much difficulty sleeping, review this with your doctor.