What may be the reason behind the sudden slow down of my web

[symakhan]

Hey Guys
I have an eCommerce website on which I sell organic skincare products. My website was running properly and was very speedy. But now, for some time, it has started to slow down. Also, sometimes it shows an error in loading when I open it on Firefox. As you know, Firefox is one of the most popular browsers, so it creates a problem for me. Most of my clients use Firefox, so I want to fix this problem as soon as possible. I am not very technical, so I don't know how to do it. I tried to contact my hosting company, but they are not replying to me. So can anyone help me with this?

What may be the reason behind the sudden slow down of my website on Firefox?
Should I update the WordPress version?
What are the other things that I can do to fix this problem?
Is there any plugin or anything that I can use to fix this?
Is changing the host company worth it?
If I want to change the web host company, Can I avail a discount on hiring a new agency? Is a website offering coupons or deals for hiring a hosting web service? While doing Google, I found some coupon websites for hosting discounts like https://www.coupongot.com/

Please help me as soon as possible.
Thanks in advance!

[therube]

> I have a ... website

URL if you care to post it.

> it has started to slow down. Also, sometimes it shows an error in loading when I open it on Firefox

How about in other browsers?
Chrome (Edge)? SeaMonkey (Pale Moon)? Safari?

> sometimes it shows an error

And the error says what?