Severus Snape is often accused of being overly obsessed with Lily Potter in Harry Potter, but two details in his story hint that he is judged somewhat unfairly. Of course, it can’t be denied that Snape is a bit of a problem. He treated Harry terribly throughout the series, all becuase of his own emotional immaturity. However, claims that Snape was a stalker might be taking things a bit too far. He was a Death Eater who maintained a love for his childhood friend, but evidence indicates that Snape had accepted that he and Lily were on two different paths in Harry Potter.

https://screenrant.com/harry-potter-snape-not-obsessed-lily-op-ed/