How can I quit the use of marijuana and defeat all of my generalized anxiety?

Multiple approaches. Important steps in treating any addiction include - develop and strengthen functional rituals to replace dysfunctional rituals of addiction, avoid contact with using friends, build social network of non-using friends. Joining a 12-step program is likely to help, esp if you find a sponsor. And most important, don't let relapse stop you from the path of recovery. Talk to ur doc about anxiety.
Start by giving MA. Or marijuana anonymous a try. If is a free, confidential ; often effective 12 step program. Work with your medical provider on anxiety.