Friends:

   Curing the agitated Restlessness and Regret!

Noticing Restlessness-and-Regret arise can make it fade away:
When Restlessness-and-Regret is present, the bhikkhu notes and understands:
There is Restlessness-and-Regret in me, while when Restlessness-and-Regret is
absent, then he notes and understands: No Restlessness-and-Regret is in me.
He also understands well how Restlessness-and-Regret arise.
He understands how to leave behind any arisen Restlessness-and-Regret, and
he understands how left Restlessness-and-Regret will not arise again. MN 10

What is the feeding cause that makes Restlessness-and-Regret arise?
There are unrest, unsettledness, nervous unease, agitation and anxiety, often
giving irrational and unwise attention to such states, this is the feeding cause
of the arising of Restlessness-and-Regret, and the feeding cause of worsening
and exacerbation of already arisen Restlessness-and-Regret.
SN 46:51

What is the starving cause that makes Restlessness-and-Regret cease?
There is the mental state of serene tranquillity, calm, quietude, stillness,
imperturbability, peace, frequently giving rational and wise attention to this
exquisite mental state, is the starving cause for the non-arising of absent
Restlessness-and-Regret, and the starving cause for the dampening and calming
of Restlessness-and-Regret, that has already been stirred up.  SN 46:51

Advantageous reflections whenever Restlessness-and-Regret is provoked:
When the mind is restless, it is the proper time for cultivating the following
factors of enlightenment: Tranquillity, Concentration and Equanimity,
because an agitated mind can easily be quietened by them.
SN 46:53




Restlessness-and-Regret is like Slavery:
Just as when a man is a slave, not independent, but dependent on others,
unable to go where he likes, exactly and even so is restlessness, since it forces
one into unwanted activity, and destroys any ease of calm. Later he is set free
from slavery, is now independent, no longer dependent, a freeman who can go
where-ever he wants. And at that release he rejoices, is glad at heart...
Such is also the blissful freedom from restlessness. DN 2

Deliberately Directing to a Conscious and Clever Centre of Concentration:
Herein, Ananda, a Bhikkhu attends to this single Focus:
This is Real, this is Supreme, namely:
The Stilling of all mental Construction,
The Calming of all Restless Activity,
The Fading of all Concern and Anxiety,
The Cooling of all Temptation and Urge,
The Ending of all Longing and Craving,
The Exhaustion of all Fuel of Becoming,
Ceasing, Peace, Bliss, Freedom, Nibbāna ...
AN V 319

DOING GOOD = NO REGRET!
Here and now the good-doer rejoices! :-)
Even so after passing away, and re-emerging,
the doer of good reaps only Joy and ease...
So both here and beyond, the wise with merit well done,
enjoys the purity of own prior good behaviour.
Dhammapada 15

DOING BAD = MUCH REGRET!
Here and now the bad-doer suffers... :-(
Even so after passing away, and re-emerging,
the doer of wrong reaps only pain and regret...
So both here and beyond, the evil wrongdoing fool
suffers the painful results of prior behaviour.
Dhammapada 16

Restlessness-and-regret is followed by worry, anxiety, agitation and attention deficit!

On Restlessness and Regret (uddhacca and kukkucca) versus Calm:
https://What-Buddha-Said.net/drops/Forest_Bliss.htm
https://What-Buddha-Said.net/drops/IV/Suitable_Substitution.htm
https://What-Buddha-Said.net/drops/III/Tranquillity_Passaddhi.htm
https://What-Buddha-Said.net/drops/II/Restlessness_and_Regret.htm

Restlessness and Regret scatters the Mind!