Issue website is loading dead slow

[Ihtshama]

Hello, my website https://professionaldesigner.ch is loading dead slow after i changed its Name Servers from Cloudflare.
Actually, it started with 500 error in backend panel, and then i removed it from cloudflare. now website is loading but takes 4-5 minutes to load a page.
Please have a look at the logs taken from Plesk. Imgur

I have already tried few threads on this forum. thank you so much for your help.

 

[MarkM]

I'd start with cleaning up your DNS;

http://leafdns.com/index.cgi?testid=98BDE58B

 

[Ihtshama]

Thanks mark for highlighting this issue. Let me google how i can cleanup dns settings. i will get back with results. once again thanks.