Dell laptop keeps freezing

My dell laptop Inspiron 5555 keeps freezing.around a month ago i had the issue of glitching the screen would show things twice in a weird green/purple colour but not it freezes all the time i watch a video it will freeze and i will be forced to restart i stop using it for 10 minutes it freezes.can u help me pls?

i have this laptopt for 2 years btw