C

a miss is as good as a mile.差之毫厘，谬以千里。the early bird catches the worm.早起的鸟儿有虫吃。it never rains but pours.祸不单行。actions speak louder than words.行动胜于语言。根据Is your sleeping problem getting better？（你的睡眠问题有好转吗？）可知，此处是说"没有。而且祸不单行。这次他们给我开错了药。你能相信吗？"
故选：C。