A because your heart doesn’t actually sink, it’s an expression of dread. :)
This sentence is messy, as well as a run-on. Here's a revised version:
"It becomes easy to gossip among the office, but remember; it is just as easy to keep it a secret!"
There is proper punctuation added to make it easier to read. It also adds personality and emotion to the sentence. Try reading the two aloud and compare them. You can make changes to it if you feel it necessary.
