External power to WEMOS mini using 3.3V 1W Zener diode
If you need 200 mA at 3.3 volts, R1 must be no more than 43.5 Ohms.  1K would drop 200 volts when passing 200 mA.

Much better to use a switch mode voltage regulator (DC-DC converter).  A linear regulator would dissipate 1.75 Watts, and require a heatsink.