Narcissistic elation
'"Narcissistic elation" or "narcissistic coenaesthetic expansion"' were terms used by Béla Grunberger to highlight 'the narcissistic situation of the primal self in narcissistic union with the mother'.
Narcissistic elation has also been used more widely to describe a variety of conditions, including states of being in love, of triumph, and of obtaining self-understanding.
Grunberger's Definition