The phrase "a deep bitterness" is correct and usable in written English.
It can be used to describe a strong feeling of resentment or anger, often in a context where someone feels wronged or hurt.
Example: "After the betrayal, she was left with a deep bitterness that lingered for years."
Alternatives: "profound resentment" or "intense bitterness."
Only years later, when she was writing "The Feminine Mystique," did Ms. Friedan come to see her mother's cold, critical demeanor as masking a deep bitterness at giving up the work she loved.
And for some, a deep bitterness also lingered.
Most Arabs wound up with a deep bitterness toward Britain and France, with most unable, or unwilling, to distinguish one from the other.
There are passages in these Hegelian lectures on history that, while seldom as replete with concrete details as are the concluding chapters of Volume One of Capital to which I have alluded, are in their own way just as bleak or even more so, suggesting that a deep bitterness of spirit may be the most obvious reaction to the spectacle of history as nearly perpetual shipwreck.
It is immensely to Edeet Ravel's credit that this novel, far from being a rant, balances deep bitterness with an abiding tenderness for the country she once called home.
It's a really acrid, deep bitterness that fills your whole mouth.
They live with their mother most of the time – a woman Paulo speaks of with deep bitterness.
The statement gave no reasons for scuttling the rally, but there is especially deep bitterness between the United Democratic Front, a coalition of groups that support the African National Congress, and Inkatha in Natal province, and their feuding has sent thousands of villagers fleeing the area.
In 2002, they had generated deep bitterness by pumping £12.95m into a trust fund for their retirement - against a background of poor performance.
On the one hand, it needs to show that it acknowledges the public's deep bitterness; on the other, it needs to negotiate a deal quickly in order to move economic recovery along.
The election campaign left deep bitterness.
