Been Hacked.. Header Java Invection

I can’t figure out where the issue is. I keep getting a header injection that causes a set of links to show up next to my header I delete the file reinstall the header and it comes back. I have deleted all my users. Changed my secret keys, removed anything that looked like an image but was not.

This site is for a homeless shelter.

I am going to drop down to the default template and remove all plugins. and see if it happens again.

Any Ideas?