@Allison-K my technical knowledge is not enough to do all this. Do you have an 'opkg install gpio' for your package that will allow gpio to work with Python3 automatically without all your fixes ? Inexcusable Omega not providing this.
The LD1117S33 (if authentic) needs minimum of input 0.1uF and output 10uF capacitors.
Also, do not use thin power supply wires. I recommend minimum of 22 Ga.
Okay, I added 47uF and 220uF capacitors to my circuit (on Vin and Vout of the LD1117 respectively) and swapped all the wires for 22 gauge. And... it works! Boots up completely and was able to setup wifi through web config and so on. Thank you!