Switching from venlafaxine to sertraline

I’ve been on 37.5 mg of Effexor for 2 years and some change. Recently I’ve been having bad anxiety and insomnia as well as just being tired all the time even if I sleep. My psychiatrist wants me to take 37.5 mg of Effexor as well as 50 mg of Zoloft for two weeks with Xanax just incase I need some calming of my anxiety. Has anyone done this before ? I’m so anxious.

Plan:

37.5 mg Effexor XR @9am (for two weeks)

50 mg Zoloft @8 pm

.25 mg xannax (twice a day if needed)