I kind of doubt that your spoke breakage was due to overall inadequate tension. If that were the case, I'd expect the non-drive spokes to break first. Uneven tension may be an issue.
If it was my wheel, I d loosen all of the spokes until there was one thread showing. Then I'd gradually bring the wheel up to tension starting with 1/2 turn and eventually 1/4 turn on each spoke. When I had the wheel adequately tensioned, I'd true it by tightening and loosening opposing pairs of spokes an equal amount.