Cant add or remove plugins or themes

It began a month or so ago when I was unable to update some plugins. I then was asked to update my theme (twenty twelve) and was not allowed to either. The message comes up as “An error occurred while updating Akismet: Could not remove the old plugin.”

Same with updating the theme. When I use my FTP I cannot delete any themes and it gives me the following error: “550 Could not delete .htaccess: Permission denied”.

Not sure what changed but I cannot seem to have access to update anything. I also do not have a back up of the site. I have tried to back it up but since it will not allow me to install plugins then I cannot instal the wp-db-backup which I understand to be the simplest solution.

I am rather new at this and have relied on the simplicity of WP to get me this far. Any help would be greatly appreciated.