What do I do?

So I was with this guy for a while (I'm f13, he is M14), and we got to the point where we trusted each other. We sent nudes and he screenshotted them. I told him to delete them and he said he did. Well about a week ago we sent more nudes. I wore underwear, as I'm uncomfortable with my body. He understands that and told me only if I wanted. I wanted, but not all the way. We also had taken a break for about 3 months in March-June. During that time (I started the break) he was talking to 3 other girls. I was fine by that, I flirted with a couple guys. 2 of the 3 girls sent him nudes and the 3rd said no. Well he got mad at one of the girls and sent her nudes around. He has screenshots of mine and I'm really scared. I didn't put my face in them, but as we are broken up for good now, I'm scared he'll send mine. He is dating another girl now, and dated another one at the beginning of the school year. So he definitely has 3 girl's nudes, he might have 5. I'm really nervous and the other girls are too. One of the girls got mad at him today and showed everyone on her bus his nudes, and he put his face in it. He denies he will but he also told the one girl he wouldn't. Someone please help.