Laptop keeps shutting off randomly then having problems to boot up

My Dell Inspiron 15 7000 7559 gaming laptop has recently been randomly shutting down, ill try turn it back on and it'll either instantly shut down again or if not instantly maybe a few minutes or hours until it does again, i have no clue what causes this but need it fixed ASAP, sometimes ill be able to game for hours until it shuts down on me then i test my luck for it to reboot and not shut down again but sometimes luck isnt on my side.

sometimes it will come up with a diagnostics page where it then runs to see if theres a problem with booting up but it always says there is nothing wrong but clearly there is.