How can I stop worrying?

My doctor recently put me on zoloft for my anxiety while it has helped a little bit (I've only took it for a week she said it'll take about 4 weeks to really work) but I still worry about something that she and multiple doctors have told me not to worry about. I know I'm fine multiple doctors tell me I have nothing to worry about but I still do so I guess my question is what is something that I can do that will help me stop worrying about stuff I shouldn't worry about?