Avoid Overrun Error in PIC18F46K80
You are getting overruns, which means the PIC isn't grabbing data out of the receive buffer fast enough.  So adding even more delay makes absolutely no sense.  Stop and actually think about what is going on.

Test with the PIC emptying RCREG as quickly as it can when RCIF indicates it has data.  If the PIC is doing nothing else, it should be easily able to keep up at 115.2 kBaud.

You may have a baud rate mismatch.  Test this by sending some characters and looking at their timing carefully on the scope.  Then also verify the PC is sending characters at the same baud rate.