Learn English – What does the phrase “tell us what you really think” mean

It's a sarcastic response.

Taken literally the sentence would mean the speaker isn't already familiar with the situation and wants more information. However it is rarely (these days never) meant literally, and is used sarcastically to mean the opposite. I.e. That the speaker is already familiar with the situation. Its meaning is similar to the expression, "You don't say?", where the speaker is acting like they don't already know, when in fact they do.

The difference between these two expressions however is that, "Tell me about it", has taken on a sympathetic tone over the years, indicating shared misery, whereas, "You don't say?", is an insult where you don't actually care what the person has to say.

There's little in the words themselves to indicate that difference. That difference is simply the connotations those expressions have taken on over time. Tone of voice is pretty critical here, because the difference between a sympathetic statement and an insulting one is simply a different inflection while saying the exact same words.

Ungodly is being used in the sense of outrageous; shocking; dreadful; insufferable, rather than invoking any of its religious meanings. So "an ungodly hour" just means "an outrageous time of day".

But how did the phrase come to have a connotation of earliness?

When people complain about an "ungodly hour", it is usually because they are forced to be awake when they would prefer to be asleep.

It's not unusual to be compelled to get up earlier than you wish. Some people must get up early every weekday just to get to work on time. And on occasion they might have to get up very early - to catch an early flight, for example.

It is far less common to be required to stay up late.

So, in most people's experience, when they find themselves talking about an "ungodly hour", it is far more likely to be an early one than a late one.