How is the adverb さっそく acting in this sentence?


別に今日だって約束してたわけじゃないし

さっそく感が恥ずかしすぎる

In the second part, it seems like she's saying it like.. "the feeling of
impatience is too embarrassing?" I'm too embarrassed of my impatience?"

Edit: From context she wants to see her crush as the talked before and said
they'd see each other again after her work was done. Now she wants to go see
him, but technically speaking they didn't promise to see each other a
particular day.




さっそく is an adverb/no-adjective that basically means "without delay" or
"promptly" when used positively:

  * さっそく始めましょう。  
Without further ado, let's begin!

But in a negative context, it can have a connotation of "hastily", "too soon"
or "skipping the usual preliminaries":

  * さっそくで申し訳ありませんが…  
I apologize for the rush, but...

  * え、さっそく?  
Huh, so soon? / Oh, already?

  * 彼は初日にさっそく失敗した。  
He made a mistake all too soon on the first day.

This 感 is a suffix. Traditionally, it follows a fixed set of difficult kango
(e.g., 罪悪感 "sense of guilt", 多幸感 "euphoria"), but informally, it can follow
various words or clauses to say _X-kinda feeling_ , _X-ish vibe_ or _X-ness_.

  * [Why can't I say してますよって感を出す?](https://japanese.stackexchange.com/q/94436/5010)
  * [Trying to understand this tweet](https://japanese.stackexchange.com/q/64462/5010)

When combined, さっそく感 forms an informal noun phrase that refers to a sense of
hastiness or being rushed. さっそく感が恥ずかしすぎる means that someone's statements or
actions are so hasty or eager that they become embarrassing.

