I have Delayed sleep phase syndrome and I'm afraid I won't wake up in the morning?

See, I usually work from about 4-9 or 12-8 or something like that, which is good with my sleeping issue. Unfortunately, I have work at 8 am in the morning, which puts me waking up at around six. I'm terrified that I won't be able to wake up tomorrow and I'll sleep through work and get fired. I'm already stressed this week and my anxiety issues have reached new levels of high, which makes my sleeping problems worse. I'm just at a loss for what to do at this point. I can't my sleeping pills, I got in late from my other job and I don't have the time to devote to sleep that I need when I take them.