The strongest ambition does not need an enemy.

Ambition that requires an enemy is really a reaction, and reactions depend on someone else supplying the stimulus. When the rival leaves, or turns out to be decent, or simply stops caring, the drive falters and you have to find another antagonist to keep it running. Wanting to build something needs no such supply, so it survives whatever the other people do.

If your motivation currently has a face attached to it, try writing down what you want in terms of the thing itself. Keep the energy and drop the target. The work usually improves as soon as it stops being aimed at a person.