Reactions to Injury: 5 or more hits in one turn

[Major Ross]

If my character takes 5 hits in one turn (and has already performed an action this turn), for the next turn - if I choose to"defend" (I'm engaged) does that count as my "DX adjusted -2 next action only" penalty? The RAW are unclear about this one. Or, does the "DX adjusted -2 next action" penalty only take effect when I actually try to attack someone and have to roll the dice?

And, good side note here, since I took the "5 hits" on the previous turn, and if both myself and my adversary had the same DX (say "10" for this example), does the -2 DX penalty simply make my adjusted DX for the next turn lower by 2, and then allow my opponent to automatically go first and attack me, since his DX is still 10 and now my DX is adjusted to be 8, because of the 5 wounds I took on the previous turn? Because, normally, since we both have the same DX, each turn we both need to roll a 1d6 to see who gets to attack first.

Thanks!

Major Ross