i think that first of all, you should apply stop loss on your trades and do not let it go so much in loss...but if you are already losing such big money...then you should think and see that whether capital is enough to cover more losses and you can handle it or not....if you can not afford more negative floating, then it is better to close it in loss and avoid further losses and save some for trading...
and i think that depends on you and if you think it will recover you can open and if you feel you get more loss then better to close and how much capital you have?and at whatt rate you buy silver?