I love the NN [name]Chrissy[/name], but have only been able to find one full name that I like for it - Chrislin - and that just happens to be the name of a girl who (maybe obliviously?) hurt me in high school. Anyway…I would love to use that name now, because I think it’s rather pretty - but should I use it considering that fact that it will remind me of her? I still have ill feelings over the whole situation, but am not in contact with her anymore.
If I had bad feelings over something like that, still - even after high school had already ended, I wouldn’t personally use it. I had a really bad experience in high school and I couldn’t imagine naming my child a name of someone who bullied me as badly as they did.
I’m of the opinion that once you have your own baby with that name, the image of your baby will replace the image of that mean girl.
Otherwise, here’s some other names that could give you [name]Chrissie[/name] as a nickname:
[name]Christabel[/name]
Crisana
Crishona
[name]Crispina[/name]
Chrysanthemum
[name]Chrysta[/name]
I knew someone named [name]Cristina[/name] with nickname [name]Chrissy[/name]. You could also use [name]Crisanta[/name].
I personally wouldn’t use a name that had a bad association for me.
The only name I can come up with for you is [name]Christiane[/name], “h” being optional. Wish I could help more! Have you considered [name]Kristen[/name]? You could look up multiple ways of spelling it with a C I’m sure.
As for the bad association, it depends how hurt you are by what happened. I’m thinking back now to high school (11 years ago) and about the names of people who “weren’t very nice”… to put it gently. 
There was a girl named [name]Elyse[/name] who was kind of a b-witch 
to me, but I can’t help but really like the name. If that name was on my list and my hubby really liked it, I’d use it. The more time goes on, the easier it is to drop old hurt feelings (again, depending how bad it was). Personally, I’d think that associating a name you love with the little baby you love more than anything is the easiest way to cut any ties that name had to anything that happened to you previously!
But, that’s my opinion, and everyone’s different! Follow your heart and it’ll lead you to the perfect name, whatever it turns out to be! 