Sorry about the trouble caused by trying LiteSpeed.
There is a procedure to switch back to Apache, we will update our plugin to show the procedure when it failed.
Usually, for the first time user, we recommend user to run LiteSpeed parallel to Apache with "Port Offset" on another port, make the switch after verification.
For most cPanel users, LiteSpeed is a drop in replacement for Apache without any problem.
Maybe your server were using certain custom Apache configurations that is not 100% supported by LiteSpeed. If need help on identify those issues, please let us know, we can either provide a work around or improve Apache compatibility.