Since you posted a copy of the .htaccess file, you clearly have access to your files, so you need to follow the articles that have been posted here before.
I’ll post them again below:
Note that we are not going to fix this for you, that’s not our job. Part of having a website it being willing to fix it when things go wrong. If you get stuck, we are here to help, but you need to tell us specifically where you are stuck, and what you have tried to fix the problem.