I have my SSL from a third party and need help installing it. Any advice?
You need to go to your third parties website and find out how to direct your url to Etsy. Etsy's instructions are here https://help.etsy.com/hc/en-us/articles/360000337787-Connecting-a-Third-Party-Domain?segment=selling
Note that it will take about three days for the transfer to complete before everything is working correctly on your end, you might not see the ssl certificate straight away.
will this help with the SSL problem?