Mac does not start anymore after a crash

HI everybody! After many years where my mac worked perfectly, i just had the first issue.. I was surfing on internet and doint nothing special till when a blue screen appears and i cannot do anything.. after 5 minutes i force the shut down and restart and the mac stops at the very beginning, when there is the image of the apple and a bar that loads.. it reaches about a third of the bar and stops (i left it 45 minutes). On top, there are blue horizontal lines on the screen. what can I do? I tried to restart with cmd and V and attached you see where it stops (i just left it again 20 mins and it won't move)

thanks a lot for your help!