What is the ruling on saying, "How awful it is for something other than what you wanted to happen," and is it absolutely forbidden or considered disbelief, or is there a detailed explanation?

All of Allah’s actions are good, and evil is not attributed to Him. However, both good and evil exist in what is created. There is no harm in describing things or actions as evil or bad; this is a description of the created, and Allah creates both good and evil, as stated in His Almighty قول: (And We test you with evil and with good as a trial; and to Us you will be returned). Evil is not attributed to Allah except in a general sense, or by attributing it to its active cause, or by omitting its doer. None of His Beautiful Names implies evil. Evil in His separate creations is a relative and additional matter; it is good from the perspective of the Lord's action being connected to it, and evil from the perspective of its attribution to someone for whom it is evil. Not everything that occurs contrary to human will is inherently bad, for what appears to be evil may be good, and He, the Almighty, said: (But perhaps you hate a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah Knows, while you know not).