I definitely recommend seeing an exotic vet. This is not normal behavior...
Also, I have read about a certain cage causing sugar gliders to have seizures that were made in 2009. I have to remember the exact brand of it.
Don't give up on your little glider. I know it's tough. I know it's frustrating. But she needs you. Just the fact that you saved her life and keep trying to bond with her shows you care. She doesn't know any better, and I am 110% sure you will not find anybody who will care for her as much as you do. If you give her away, she will only get worse due to her environment changing and make her stress out.
Gliders have different personalities. All are different. There are no 2 gliders who are EXACTLY the same. Maybe Creme is a little bit more independent and prefers to be left alone?
Give it time before you make your final decision. Gliders need time and dedication. Some Gliders take MONTHS sometimes an entire year to bond with their owner! I already had mine for about 2 months and he still won't let me cup him in my palm... It just depends on the personality. They're all different. Especially the females, they're a bit more nippy and crabby. Women... Lol.
Take the bites, do not pull away or else they will see that as a way to get what they want. Try dipping your finger in honey or greek yogurt so she can lick it off and associate your hands as a positive thing. Talk to her in a positive tone. try to pet her even when she won't let you. Just give her time and let her see that you are only trying to love her and care for her, not hurt her in any way.
Good Luck