Background to all posts turned black

Something has happened to turn all my white text space into black, so the text isn’t visible. The blog site is: KafkaesqueBlog.com or https://www.kafkaesqueblog.com/

The blog always had a black background in the very back, but the main section in the middle was all in white. The whole look of the actual post itself, if that makes any sense.

I feel like an idiot because I don’t know what happened and all this coding is beyond me. I’ve tried to read up on solutions, but I don’t know what I need to do. I think the cause may be 3 plug-ins that I installed last night, so I have de-activated them. (Like, WordPress Tinymce visual editor buttons. I also deleted a 4th one that was a “Follow” button thingamajig.)

I wasn’t sure if I should switch to a different theme instead of my current Twenty Eleven, as one thread stated, because I’m scared I may lose the customization a friend did for me with the menus. That took him hours with setting up navigation or “children” or something, and I don’t want to lose it.

I haven’t touched anything with CSS. Frankly, I wouldn’t know how.

One thread I read on WP said something about how it might be a bad Phishing link that got inserted? I have no idea what that means or how it may have happened.

Can anyone help? I’m completely desperate and have absolutely no idea about any of this technical stuff. Honestly, I’m close to tears. Transitioning over to a self-hosted site has been nothing but difficulty.

I’d be grateful if any of you can help me with this latest glitch.