Random fps drops till its impossible to play

[Kirika-]

Your nVidia graphics card drivers are way out of date
SYSTEM_GRAPHICS_DRIVER_DATE 11/22/2020 03:00:00

Head over to nVidia's website and download the current drivers for your GTX 1650.
Then Google search for the utility called "DDU", download and run it, which removes video card drivers/settings/registries completely, that helps correct issues with different revisions and versions of drivers orphaned or conflicting on a computer causing issues, then install the new drivers you downloaded.

Another thing to check is the CPU performance and temperatures. A Core i5 4th-gen CPU is fairly old, if it is also in an old computer, the thermal compound on the heat sink may have broken down/dried out and is not transferring heat as efficiently as the system needs. An overheated CPU slows itself down, directly hitting performance in gaming.
Google search for HWMonitor, download and run it in the background during a gaming session to see what the temperatures reached and what the CPU performance did while gaming.
If the CPU gets too hot (over 90c) and the clock frequency drops low, then open up the computer to see what is causing the CPU to not be able to shed heat per requirements.
As I said, look for bad thermal compound and also check for proper airflow, dirty heat sinks and fans, and loose heat sinks.

Also, FF14 has been known to have issues in some cases when not installed on the OS drive.
If you have room on your OS drive, install the game client there.