Site keeps getting 500 Internal Server Error and loses connection in admin panel

Since May, my website, which is hosted by 1and1, has suffered the brute force attack. It goes without saying how difficult that ordeal was, as my site is growing and cultivating a dedicated audience. Last week, I got a WordPress specialist to block the .htaccess file, which immediately ended the continuous logs on the website. However, the posts when shared on social media still had the “Internal Server Error. Please contact server administrator” message on them, which is both embarrassing and frustrating. Meanwhile, on the backend, during every post, the connection ends and I get the “Connection lost. Saving has been disabled until you’re reconnected. We’re backing up this post in your browser, just in case.” message. Other than that, I’ll be in the backend and will get the 500 Internal Server error message. As the problem continued to persist, I reached out to my WordPress tech and he confirmed with me that the brute force attack was over, as did 1and1, telling me my server error logs showed nothing out of the usual and no files are corrupted. With that being said, I am out of answers and soon to be out of a business, because there seems to be no fix for this nagging problem.