What am I?

I can hold
The weight
Of worries
Right alongside
The deepest
Of joys
I’ve had lots
Of experience
Held them for
Many others
Over the years
Moms and dads
Grandmas
Grandpas
As their arms
Held the tiniest
Of beings
Overcome
With love
Responsibility
And exhaustion-
One gentle push
Of their feet
Against the floor
And fears fade
With my back
And forth rhythm
That lends itself
To lullabies-
It’s okay
Sit down
Take a breath
You can trust me