It most likely is the guilt he is feeling......he will get over that.....but in the meantime......I don't know if you and your husband have experimented with talking dirty during sex, but when my man is having a little trouble (for whatever reason and there are many that affect us all) I talk dirty to him and it usually does the trick.
Sometimes we just need a "little extra" stimulation.
Good luck.
One would think that guilt would have an impact on ED not ejaculation. Age, exercise, eating/drinking, medicines, sleep, & sex frequency data not given. Maybe time is the answer, though the problem may not be guilt.
I would say it has everything do with guilt. A fews months ago I cheated on a girlfriend and i could not ejaculate on three seperate occasions afterward. There's probably many things bouncing around in his head and it has nothing to do with you or some physical issue. Over time he will get over it (as he should, he's a lucky guy) and things will return to normal.