Ex stalking me for 3 years?? HELP

So I have an ex that I have blocked on social media but he still uses other peoples facebooks an he messages my friends to contact me. Every time we get in contact it’s “I’m sorry” and every time the conversation ends with me saying “it’s okay I’m not mad, I just can’t be friends with you.”

However I switched jobs about a month ago and one day I was goofing off posting stuff on my Snapchat story, and someone showed him and the next day he came up to my job telling me the same sorry stuff, asking if I had a bf and if we could be friends..that if we can’t be friends he’ll just come up to the store to see me. I was telling him “idk about being friends”

It’s the same repetitive conversation with the same out come..for the past 3 years. There was about a year where we didn’t talk but it’s like he tries to talk to me every 6 months or so despite me telling him I can’t, it’s gotten to the point I don’t even open his messages.

..Well last week he came into the store and I saw him for a split second as he was leaving, I didn’t see him come in and to my knowledge he didn’t buy anything and idk if he used the restroom. But my current bf says he was probably scoping out the place. Now my dad and bf are telling me to carry my pepper spray with me to work. He hasn’t been hostile or made any threats, just won’t leave me alone.

......is this very serious and I just don’t see it? Should I contact the police?

I will give updates.. on