Hi, you are experiencing shift work sleep disorder. This is common when there is a disturbance in normal sleep pattern. This happens when you force yourself to work in the night for few days and leads to a habit. There will overall shift of the sleep cycle. If you continue this for longtime then it can be problem and can lead to chronic insomnia.
The sleep problems can be resolved by transferring from the night shift or by adopting a daily sleep routine that is consistent seven days per week. Chronic insomnia may develop in individuals who work the night for a long time.
There is nothing to worry, you can go for non-pharmacological means; Photo therapy, maintenance of sleep hygiene. The therapy consists of light therapy where you will be exposed to specific amount of light during day to alter your abnormal melatonin turnover.
I suggest you to consult physician. Take care and regards.
It's not ideal actually. It throws off the circadian rhythms of your body and can affect all kinds of things. For example, your body heals its tissues primarily between 11pm & 2am. So if you're awake, you're not giving your body the time it needs to heal itself. This can result in an accumulation of pain in your muscles, AKA fibromyalgia. You should try to get to bed earlier so you can wake up at a more normal hour. If you have trouble falling asleep, try to do things in the evening that make you sleepy. For me, reading knocks me right out. Also, avoid things that overstimulate you in the evening like using the computer or watching TV can really make it hard to fall asleep. Trust me, as someone who battled sleep issues most of my life, it's not something you want to be dealing with in the long term. It's miserable. So take the time this early in your life and set a schedule for yourself that can help you to feel as good as possible. It will pay dividends for you for the rest of your life! Good luck! :)