There are alot of times where you get an error saying that your site cannot be reached or just take a long time to load.
There are a few things you want to check before thinking that your website is down or broken.
1. There is a chance that your local IP address may be blocked by where you website hosted. Go to a website like iplocation.net or ipchicken.com to get your local IP address and contact your hosting company to see if you are being blocked. They can remove the block and should be able to bring the site back up.
2. If you have already tried the first option, the next is to contact your ISP (Internet Service Provider.) There are many times that your ISP blocks your domain name because they think the site is being hacked. Just give them a call to check.
3. The least common occurrence. ICANN sends out a verification email every year to the email you used to register your domain with. If your email is out of date, you will never receive the email and ICANN puts a hold on the domain since the domain was not verified. It is recommended to contact your domain registrar and make sure all the contact information is updated.
If you are still unable to see your website after checking the above three options, contact your hosting provider to have them review your account.
Just reply to the thread if you have any questions regarding this.