None of my blog post links work

Here’s the link to my blog: https://leadershipskills.successtelevision.biz/

If you click on any of the titles you will get a 500 redirect.
I’m going crazy tying to figure this out. I got rid of plugins. I upgraded to 3.1.1. I created a mysql database which is way over my head but the system said it work for allowing a back up.
Now, none of the links works.
Can someone help me with this???