Regarding Time to First Byte problem

Hi,

My question is about first byte time ! Unfortunately, first byte time score of my blog/website is F for 2 days! However, it was A for a long time!

If needed, please see the url given below!

https://www.webpagetest.org/result/190331_8D_7c09ea378501f2585a1021ce9822ee3e/

Honestly, I could not find what its reason was! I need your help! What should I do to solve this problem?

Thanks for your support right now.

Best regards.

Pelin