major issues with multiple sites and need help!

I am looking for some advice on a very knotty WordPress Problem! I’ve been doing WordPress sites since 2009, so I’m certainly not a newbie, but I am stumped.

My site(s) were hacked at GoDaddy and I changed the NS to Bluehost and gave them fresh installs there and rebuilt one of them and installed a brand new template. Yesterday, that template wasn’t working and I had a white screen. Bluehost says it’s the template…why would it have been working all week? They won’t help. They say it might be WordPress (don’t think so) and meanwhile, I can’t get it resolved. I also have 4 other sites that are also acting strangely, not displaying any slideshows from plugins. This sounds systematic to me. Do I need to move my sites? Have you encountered this? I am not sure what to do.

If you have encountered anything like this or have any insights, I would like to hear from you ASAP.
Thanks,
Jenny