Finding a good host for your site(s) is always a challenge. Outages, slow loads, mysterious server emails and support people who don’t help you are all things that are endemic to the hosting biz, sadly. For me, downtime is the bane of my existence and it happens all the time, with all hosts.
Despite these issues, our current host is SiteGround and they seem to be doing an ok job at keeping things running and wrangling the errant server. For uptime, they are definitely the best I’ve used.[as of Nov 2017]
If your site is down and you’re not sure if it’s just your connection or the server really is down, you can use https://www.downforeveryoneorjustme.com/ to check. I also use https://www.siteuptime.com/, which offers free monitoring of one site.
You’ve got to stay on top of your sites. Your host will not tell you if your site is down and more often than not, they’ll deny it. So be proactive and monitor your sites daily.