wrong voltage when splitting from 5V to 3.3V
No need for a regulator. Buffer with an opamp. Have OUT connected to IN- and your +3.3 from the divider connected to IN+. Remove other connections to the divider. Run the opamp from the +5V rail. Use the opamp OUT to run the +3.3V rail with the pull resistors etc. Make sure the opamp can supply the current required by the accelerometer.