There is not much way to tell what may be wrong. Please give a lot more information. Does the ATmega328P have a bootloader on it, and if so, what bootloader? What selections do you make from the Tools menu in the IDE? Version of IDE and OS? Set the IDE preferences to show verbose output on upload and show the results of an attempted upload. Show a photo of both sides of the board when connected using your FTDI. Show a schematic of the PCB. I suggest removing the 1K resistor to ground. Do the loopback test mentioned in one of the pinned posts on the Installation and Troubleshooting forum and tell results of that. Tell what happens with the flashing of an LED connected to PB5 during upload and during reset of the MCU.