Should I Keep Taking Ambien, Switch Back To Hydrocodone, Or Alternate Between Them To Avoid Dependency After A Major Surgery?

Hi, I just had a major surgery three weeks ago and was prescribed hydrocodone and ambien. I am still experiencing pain and discomfort but I stopped taking hydrocodone after 4 days and have been taking Tylenol since then. I took ambien after that for four days and then stopped. Due to the pain I bought some extra strength Tylenol PM but it has had no effect to help me sleep, so I am back to taking ambien to get some sleep on weekdays. I have been taking ambien now for four days and I was wondering if I should take ambien to get to sleep tonight or if I should try the hydrocodone? I don’t want to develop a dependency to either but right now I don’t know what else to do but to take something to ease the pain and help me sleep. Would it be better to change things up and take hydrocodone for a bit and then switch back to ambien? What do you suggest?