Why is my basil plant wilting after I pruned it?

I bought my basil plant over 2 months ago, it's around 2 feet tall and it has flowers. I read somewhere that it would be better if I prune the basil and not let it flower. I cut the stems and now it's about 1 foot tall... A week after I pruned it, the leaves started to wilt and the stem is turning into brownish color (it used to be green in color). What did I do wrong? Can I still save it? Please help.