TMR Hall Joystick for Nintendo Switch/OLED/Lite Joy-Con, Zero Drift Hall Effect Joystick Replacement for Switch Controller, Tunnel Magnetic Resistance Thumbsticks with Tools Kit (1 Pair)

Games control whether or not the D-pad is supported as a optional direction input unfortunately. But even if you could use the D-pad, the broken thumbstick is still making inputs, so it would still be messing up your games without a means of disabling it. I would say learn to replace it, took me like 45 minutes to learn how to replace the shell back in the day. https://www.amazon.com/HandheldDIY-Replacement-Controller-Thumbsticks-Gaming-Console/dp/B0D5LLMTCT https://www.ifixit.com/Guide/Left+Joy-Con+Joystick+Replacement/113182