My doctor stated that my anxiety is what is leading to my episodes of spastic lower back pain. is this even possible? i don't believe that at all.

It is possible...: Especially if anxiety or stress is associated with reduced activity or a history of back pain. Inactivity due to anxiety and stress or chronic tightening of muscles due to anxiety and stress may lead to discomfort, or weakening of muscles that contribute to back pain and spasms. Were any treatment options discussed? If not it might be worth having that convsersation. Many options are available.