1.00E-35 X 3.00E8^2 = 1.00E-35 X 9.00E18 = 9E-17 Joules of energy were evolved in this reaction. Seems like a really small amount of energy considering one Joule is the force it takes me to lift one kilogram for just one second. This amount of energy is .00000000000000000000009 Joules. Really tiny. But, let's say that there is a mole of Hydrogen in the bomb. Not out of the question considering a mole of Hydrogen only weighs about one gram. To find the energy in one mole of this reaction, we multiply the Joules evolved by Avogadro's Number, 6.023E23.
9E-17 X 6.023E23 is about 5.4E7 Joules of energy. That's a lot more, but still not a terrible amount. What if there were five moles, so just five grams of Hydrogen fusing to make Helium?
9E-17 X 6.023E23 X 5 is approximately 2.7E9 Joules.
As you can see, as the amount of Hydrogen increases, the Joules also increase to become very large. So, the energy in a Hydrogen bomb is dependent simply on how much Hydrogen you want to fuse into larger elements.
Again, this is simply how I understand these two processes to work. I hope this helped.