Harassment?? Scared 😳

So I go to college and of course if you go there you add people or follow people on social media from the same college bc why not? So this guy requests to follow me on Instagram and I let him bc I saw that he goes to my school and all of a sudden he starts DMing me about how I'm "so pretty" and he seemed nice at first. He asked for my Snapchat and I gave it to him I have a lot of people from school on there. So he snaps me and starts sending pictures of petrified wood and a rock collection and then makes jokes about his penis like somehow they were related idk maybe he thought of is as the petrified wood and then he asks if I want to see it and I said no bc I really did not want to and he sent it anyway! And I told him again that I didn't want to see it and he continues sending pictures like that so I blocked him on both Snapchat and Instagram. The right thing to do right? Then about two days later a random number starts texting me. my number isn't posted anywhere I don't just give it to anyone. It's him. He wants to come over. I block him. Another number shows up. It's him. He wants to hang out. He wants to know what I'm doing. He knows what hall I live in now. And I'm scared.