I need help understanding this poem

Hello,
I think I am pretty good at understanding English considering it is not my native language. But there are a lot of phrases (and idioms?) that I am not familiar with in this poem, so I am having trouble understanding the meaning of it:
What is a "star struck death"? And a "gold disease"? What does it mean that a "promise gives way" to these things? Also, I thought a "hollywood end" was a kind of sappy, unrealistically happy ending to a story, but it doesn't really sound like it is here, since he was "a once great man who found death on his knees" (nothing happy about dying). What does he mean with a "hollywood end" here?

I have a hunch from looking at the title that the gist of the poem is something good turning into something bad... but I would love to get some help in understanding its contents better! How would the English experts on this forum interpret this poem?

I don't think it's meant to be understood intellectually. Use your heart, not your head.

Here are the idioms I think the poem is referencing:

daydream - thoughts imagined while resting during the day, usually behind closed eyes but not before sleeping. Thus, one's hopes, desires, and plans.

star-struck - "Star" means "famous person." "Star-struck" = being bewildered when meeting someone famous or whom one respects.

Hollywood - a proverbial place of fiction and deception. Actors are notorious for "partying hard:" wasting their lives with sex and drugs and short-sighted pleasure in general.

on one's knees - a posture of complete weakness and respect. How one begs for help from someone. Also, how one vomits into a toilet. This idiom has both religious and vulgar connotations at the same time.

cash in - at a casino, to exchange chips for money. Thus figuratively: to quit some activity and go home. To die.

crash and burn - to be consumed by addiction to something, like drugs.



So I see it as a word-painting of someone who had great hopes but fell into destructive addictions.