Vick -- who cancelled his book tour after "credible threats" were called in to several Barnes & Noble stores across the country -- says he refuses to let his haters control his life.

Vick's rep tells us ... "Regardless of the past threats, he has millions of fans around the world and has been receiving countless messages of support. He will continue to keep an active schedule working with charities."

Wayne suffered the seizures Tuesday night after shooting a music video in L.A. and was subsequently taken to Cedars-Sinai hospital. Weezy was released several hours later, early Wednesday morning. We’re told he’s doing much better now.

It’s not the rapper’s first encounter with seizures either — TMZ broke the story … Wayne suffered two seizures on board separate airplanes last October.