it's purely lousy timing.
you have nothing to feel guilty about - as you did not get sick on purpose.
the correct thing has been to stay at home and get your strength back, and your husband sounds like he does not blame you either .. indeed , as you said, he has made the best use of his time.
like the lovely tinkerbell advises -- go out for a meal with him. and whilst there - tell him that you will have another few days off in the near future, and then you will make up for missing this one.