Snape as having been loved.

[eggplant107]

No: HPFGUIDX 136396

Question: "Has Snape ever been loved by anyone?"
 
JKR: "Yes, he has, which in some ways makes him more culpable even 
than Voldemort, who never has".
===

If Rowling says Snape is more culpable than Voldemort in ANY sense
then Snape most have done something pretty horrific, like murdering
the wisest kindest character in the book. Some things are beyond
redemption and that is one of them. I think the person who loved Snape
was Lilly in her 6th year, she didn't start going with James until the
7th .  In the 6th they both would have been taking Advanced Potions
and both were good at it. In fact I wouldn't be surprised if Lilly
didn't give him the playful nickname "The Half Blood Prince".

Eggplant