Unless you find some new laws of physics, your will use the energy
to power a reaction drive, sending photons in one direction and
your ship in the other. You will not exceed the speed of light.
Therefore, you cannot reach Pluto in less than 39 hours (as I recall.)
If you intend to use the energy to accelerate to .5c and then
decelerate,
your matter-antimatter drive will need to to use twice the mass of
the ship. That's a lot of antimatter. Production of that amount
of antimatter will take several orders of magnitude more energy than
the human race has generated in all of history.
Conclusion: find some new laws of physics.