Bad sparring partner

I just started sparring a few weeks ago and I’ve sparred with a guy who keeps going hard even tho I ask him to go light and technical. The last time we sparred I stopped in between the spar to let him know to lighten it up but he continued to go hard. Knowing this I still remained calm and continued to spar light with him while he tried to take my head off because in my head I felt if I started going hard he would go harder and i would end up with a concussion or something. I was just getting good at sparring and I feel like this just destroyed my confidence. If anyone has experienced stuff like this how do you handle a situation like this.