Its still accessible - you just need to set an exception in the browser your in - this is an example in safari
However the SSL cert - it depends on the ssl cert you had installed and if your on shared hosting, vps, dedicated, cpanel, direct admin etc etc
Too many queries to give an accurate answer
However if you have some sort of managed server from a host then open a ticket with them and tell them the SSL isnt working has expired
If you have cpanel / whm then go there and look for ssl and run the Auto SSL feature
If you have a purchased SSL then check you have renewed the purchase and if so then add the relevant ssl certificate to the ssl manager at your hosts
If your on cloud hosting here then open a support ticket and let them know
SSL.m4v