hyundai coupe 1.6 y reg?

ive let my car go really low on oil. now topped it up not quite full but the car now is playing up
its screeching when i put it into gear.

i did manage to get it into gear and after putting in the oil it seemed to drive ok.

but parked up over night same thing happened again still managed to get into gear and move it
whats wrong is it because i let it go low on oil or is there another problem.