I bought a Vanilla Visa gift card and bought 75$ worth of stuff online 2 weeks ago (worked fine, typed in info and all went well).

Then, I tried to buy something today with the same card (still has 100$ on it) and PayPal keeps saying it can't verify the card, and that its being declined
Could someone help me out on this issue

Maybe Paypal is not able to confirm ur remaining balance with Vanilla Visa

I'd suggest contacting Vanilla Visa & confirming ur remaining Balance, then contactin Paypal for an explination of there Denial/Decline

just tried both, for some reason it wont let me do anything really. They said it cannot confirm my address.. yet i bought something with it before..? I dont understand what the problem is.

Try later sometimes paypal waits for alll transactions to go through. Wait afew days and try