My English teacher is stalking me! ?

My English teacher (also my homeroom teacher which I have everyday) is stalking me. First I thought I was overreacting, but its serious. First, I was in the hallways and I was going outside to call my friend with my cellphone. We aren't allowed to used cellphones inside the school, which is why I went outside. I sit down on the curb and take out my phone and the teacher walks up to me and hes like "If I see you using that phone again, it's mine". I just thought he was maybe a little confused or something. Anyways, then the next day me and my friend were going out for lunch. We decided we should go to Pizza Pizza. When we were walking there, the teacher was in the parking lot. Then there was some other girl and she was like "where are you going" and my friend yelled "We are going to Pizza Pizza" and my teacher heard so he walked into the restaurant the exact time we went there. I thought it was a coincidence, but then we walked to the mall and I was looking at tops. My teacher was like right behind me looking at tops (girl tops and hes a guy!!). I got scared so I just left and when I was leaving he was following me and when I was at my locker, he walked right by and and just stared at me the entire time. When I enter cl, he's like "kk guys, this entire cl failed the test except for one person who got perfect - Janie! *claps*" I was shocked! I didn't even study for the test and I got 100% and the rest of the cl failed! OMFG! And when I left the cl he said he likes my phone and I'm like okkk w.e. Then yesterday at lunch, he walks up to me and hes like "where are we going out for lunch today?" I just ran away since I'm scared. Hes like 58 years old and hes really creepy and when he marks you on tests, its like he pulls marks out of a hat. Also, one time I was wearing heavy ear rings and hes like "You should take those off, I wouldn't want your beautiful ear lobes ripped apart" and I was like w/e and i left. I told my mom and shes like im overreacting but I know I'm not. And like everywhere I go I see him. what should i do!!!