Cannot update/ install any plugins

Having major problems with my site http://www.littlesugarsnaps.com

It’s intermittently crashing, up to 20 times a day for 5 minutes at a time. Been like this for 2 weeks. Tried disabling plugins, optimising, everything up to date, nothing helping.

Now to top things off, I am unable to update any plugins. I click the button to update and nothing happens, except that my site closes down for 5 minutes.

Clearly I have serious issues here. Please can somebody help or recommend someone I can talk to?

Thanks in advance….

https://ww.wp.xz.cn/plugins/woocommerce/