Meaning of the expression “Eat sh**”

What does the expression "eat shit" represent in the following sentences?

Eat shit, I'm not going to do your dirty work.

Is this similar to "I dislike doing your dirty work"? Or does it mean "Go to hell."?

Eat shit, I am not going to follow you.

I found many different interpretations of this expression on Urban Dictionary, so I am quite confused.

Please could someone clarify.

Eat shit also eat crap means:

Submit to degrading treatment, as in He refused to eat shit from the coach. James T. Farrell had the one term in Grandeur (1930), They don't eat nobody's crap, and Mario Puzo the other in Dark Arena (1955), He'd eaten shit all week.

[The Dictionary of American Slang, Fourth Edition]

In your context, it literally means:

You (yourself) submit to degrading treatment, I won't submit (myself) to any degrading treatment.

which could mean the speaker is not agreeing with the plan the other party suggests because he feels it is degrading and not the right thing to do.

Eat shit is an imperative sentence. It could also mean "no (f***ing) way, over my dead body or f*** you" depending on context. Without any further context, it is not easy to determine what it means. But it is a strong objection to the other party's plan or suggestion.

Yes, it is like "(You) go to hell". It is an imperative construction, and it is telling another person what to do. If there is sh** to be eaten, it is not going to be me, but you, who eats it. Of course, we're speaking about figurative sh**, "dirty work".

The term, eat shit, has two different meanings. Wiktionary definition:

As a verb:

(slang, vulgar, of a person) To fall and land on one's face.

As a command:

(idiomatic, vulgar) An expression of discontent or aggravation to another party.

So, the usage of your given example is as a command. Here is the PG version:

You dissatisfy and aggravate me! I'm not going to do your dirty work!