so i was selling some gucci glasses on ebay and copied the image from gucci website, and now gucci is sueing me, but is it really infringement if the image used from their website was infact used to sell the very exact item they made?
Yes. They're not saying you misrepresented the sunglasses, they're saying you took their image without paying for it. The photo image is their IP because they paid the photographer and you didn't, so they presumably own the photo's copyright. A copyright means exclusive rights, so only they can use itm unless the license their rights. So you've infringed on their copyright, and if they do have it copyrighted, they can sue you.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.
You took something that did not belong to you -- someone else's photograph. You know it was wrong. You will be found liable for copyright infringement if you defend the lawsuit. You need to hire an intellectual property litigator very soon to negotiate a settlement.