Do I need to reinstall Safari?

I apparently have a virus that pops up with full screen ads and warning signs/alarms that "this Mac is infected, contact Apple immediately." Various downloads then begin. I constantly restart Safari to stop the screens and warnings from popping up. My ad blocker is activated, but it doesn't seem to help. I have tried everything that I know. Should I simply uninstall, and then reinstall Safari? Will this affect stored data, saved pages, files, etc? What are the risks? What will I lose? Is there something else I should do instead? The pop-ups, alarms, and pages are becoming annoying.

Here is one example of the warnings:

Your OS Yosemite is infected with (3) viruses!Your OS Yosemite is infected with (3) viruses. Our security check found traces of 2 malware and 1 phishing/spyware. System damage: 28.1% - Immediate removal required!The immediate removal of the viruses is required to prevent further system damage, loss of Apps, Photos or other files. Traces of 1 phishing/spyware were found on your OS Yosemite with.Personal and banking information are at risk.To avoid more damage click on 'Scan Now' immediately. Our deep scan will provide help immediately!4 minutes and seconds 17 remaining before damage is permanent

Thank you in advance for any assistance.