Is there a drug that helps treat social anxiety that doesn't have anxiety as a side effect?

There are some - but: Some have their problems. Benzodiazepines don't cause anxiety until trying to reduce or stop them & are potentially addictive. Serotonergic antidepressants can cause anxiety until taken at reasonable doses for a period of time. Buspirone is weakly effective & no anxiety provoking properties. Inderal (propranolol) can help anticipatory/performance anxiety & moderate general anxiety safely & doesn't cause anxiety.

Yes: Anxiety often relates to hormonal imbalance such as adrenal fatigue/adrenal insufficiency. Also related to low serotonin state. I have even seen food sensitivities cause it. As well as magnesium deficiency. Seek a holistic physician for eval. A good med to try, if needed would be a beta blocker like toprol (metoprolol). For supplements look into magnesium and 5-htp.