Fontello-embedded.css and speed !

Hi, I'm not a developer, just a blogger, and please excuse my english. (this post begins so well ^-^)

I've made several speed audits on my homepage and performances are very bad, especially on mobile. It appears that the fontello-embedded.css has a very high impact on speed page. Please check my site (https://lalutotale.com) on pagespeed insights or GTMetrix and you'll see the problem.

I don't know how to reduce this css. In fact, i don't even know impact if I delete this font icons css of my site...

Do you know any way to reduce the impact avec this fontello-css please ?

Again I apologize for my very bad english.

Thank you ! Lucie