My LPS, including Caulestrea/Candy Cane Coral are also suffering lately. Let's talk about it before you throw in the towel.
IME, LPS need about the same or less water flow than Soft Coral, like about the same amount of light, like Alkalinity of 8-10 and Ca of 300-400. I believe that changing the Activated Carbon in my tank will help since it's been weeks. LPS Coral also do well with periodic additions of Mg, Sr, Mb and a little I. So how is your tank doing in this regard and how do we add these, if deficient?