SSL handshake failure

Hello.
I have an issue when trying to access my website (https://donau-os.com) telling me Cloudflare’s SSL handshake has failed. This error has been persistent for the last few days and Cloudflare’s website has informed me that I should get in contact with my hosting provider.

The error also affects all subdomains.

Thank-you.

@badbot
Hello!
Yes, under main domain I found the following: wc1.unaux.com
I bought the domain name separately.
Thank you!

I have three active subdomains:
tracker.donau-os.com
liveupdate.donau-os.com
test.donau-os.com

I have temporarily disabled CloudFlare on my website.
The DNS name servers are subdomains of unaux. Should I provide those to you?

Will I be able to start using Cloudflare again afterwards? I need SSL.