Replace spoke, true wheel to right spoke tension.
Not sure about the gearing. Search for any sign of damage to cable housing (like has it been pinced or disformed in the fold). If so change cabel/housing. Try to pull the cabel out of the housing, lube innsid and reconnect.
If no sucsess replace shifter.
Still problems? Throw bike out the window from 5th floor. Remember to open window first.