If you have written a call option & when markets falls then things are going in your favour only.
If the underlying is falling then you are benefited & things are going in your favour only.
Had it been if markets/underlying was going up then it would be a case where things are not going in your favour.
Rest , regarding exiting the position, that has already been answered before my reply.
Yes u can square off your position anytime before expiry by buying the contract of same strike price, same expiry. But mind you, if u have written a call then you need to buy back the same CALL only to square off. Don’t get confused that if u have written a call then buying a PUT will square off your position. No it wont !!
That will create one more open position.