My sleep pattern has changed a lot and for a week now I have been sleeping for 4-5 hours during the day and I can't fall asleep at night. What can I do and can I die from it?

Well yes, but it has to be going on for some time, and sometimes it’s a sign of an underline health issue that’s the real threat. Of course, lack of sleep can cause dangers because you may get drowsy when driving or working with something dangerous that requires focus. But when you usually can sleep try to stay up as long as you can to work your way back to a nighttime pattern.
No electronics at night. Maybe a nice bath in Epsom salt before bedtime. If you are menopausal this is normal. If its work-related stress then that can happen as well. But I would see a doctor if this continues on. Certain ailments or conditions can be a problem.

Maybe during the day set an alarm for one hour during the time you usually sleep so you won’t feel too rested and can hang on till late. Don’t do anything stimulating before bedtime or eat heavy.

Make your room a nice cool dark cave. And maybe try some Melatonin and don’t get stressed out about how much sleep you get. Its more important to get quality sleep at night.
These are all things I have done to help with sleep when I was having problems with my sleep pattern as well. I found that Melatonin didn’t work for me but I know some people who sleep well using it. It’s over the counter and won’t leave you groggy when you wake up.
Mine was caused by menopause and the lack of sleep made me stressed which only made things worse. So try not to stress. But get a physical to make sure its nothing else. I went from 4 hours of sleep to sleeping 6 hours for many months to finally being able to sleep 7 to 8 hours straight. I still go to bed late but I try to make sure I’m in bed no later than 3 am. and sleep no later than 1030 or 11. When I’m busy all day, I can actually be in bed by 11pm and up by 8.

You’re still getting some sleep, I wouldn’t panic, but you should try to get to the root cause.

Are you stressed out about something? Maybe go to the doctor if it persists, make sure they test your thyroid. Are you also very hungry? Skin dry? Hair falling out? Eyes hurt? Feel impulsive? Anxious?

Try to relax at night, try some breathing exercises for relaxation. No caffeine before bed time, make the room dark.

Why did you sleep pattern change? Was there something going on (new job that required you to get up at a different time, new baby that wakes you up 3 times during the night, etc)?

Try soldiering through a day without sleeping, no matter how tired you are.

Have you tried stopping the sleep during the day so you’re forced to sleep at night? When I first quit my job to become a stay at home mom, I was taking afternoon naps that interrupted my night sleep.I spoke with my doctor and he suggested that either change my daily routine to accommodate my naps or figure out a way to stop the naps.

I didn’t like my day being broken up by the naps, so I started paying attention to when the nap was coming on and I started going for a walk when I felt that first spurt of drowsy. By the time I returned home I was wide awake. I found that I slept better at night. It was a deeper sleep and more like 6–8 hours of good sleep. It took less than a week for my system to get used to the new schedule. Once my body adjusted to what I preferred, I had retrained myself to not “need” the afternoon disruptive sleep and I could easily make it to going to bed at a regular time every night and getting a well rested sleep. Just be sure that once you find your happy place that you stick with that routine without fail

Do what @ragingloli said and try listening to ocean waves at night or some other calm music.

I have insomnia. I understand.
Take the naps. Don’t worry about it interfering with night sleep. Take it when you can.
Get rid of electronics that use blue or green lights. Clocks, chargers, anything. Only use red lights.

As long as you are getting some sleep then no, you won’t die.
Plenty of people who work night shifts sleep during the day in order to be awake at night to perform their jobs.
But if your sleep pattern is making your life difficult- such as interfering with school, work, and social activities, then you should talk to a doctor so you can discuss all the possibilities to identify what has caused your irregular sleep. Only once you have determined the cause will you be able to know which method to use to correct the problem