Why is my website blacklisted and how can I fix it?

I own a small business. I woke up one morning, tried to visit my site, and avast blocked it. I deleted my entire site and reset my entire database. The only thing that remained the same was the domain name. I then re-created the website and the problem is still there.

How do I fix this problem? My website is Accountantmarketingagency.com

And what does the message from avast say?

The avast online security says: Warning, this site could have harmed your computer.

Is that all, Does it say URL:Mal ? If so it mean blacklisted URL or IP

Something for you to fix >> http://retire.insecurity.today/#!/scan/3438b82e0a1587eb2776dc21bd99805e7f4f4285196eb236e5785fcc891eddd7

How to report it to avast lab >> https://forum.avast.com/index.php?topic=14433.msg1289438#msg1289438

Yes that’s exactly what it says.

Awesome, how do I go about fixing the vulnerabilities shown at that link?

Awesome, how do I go about fixing the vulnerabilities shown at that link?
Who made your website?

I did using the following customizable WordPress theme: https://themeisle.com/themes/hestia/.

Furthermore, here is a virustotal scan showing a detection rate of 0/63 and a urlvoid scan showing 0/34.
https://www.virustotal.com/#/url/45d34a051418690539031bbc962ecb96af451d9a4e72dbfe10c5a1ad9aa34514/detection
http://www.urlvoid.com/scan/accountantmarketingagency.com/

I removed accountantmarketingagency[.]com from our blacklist, it should not be flagged as unsafe from now on.