If I know he's had a bad day (he'll usually text me or let me know when he sees me that his day was bad) then I tend to stay out of his way and let him do whatever he wants. I'll usually rub his neck/shoulders or scratch my nails down his back (something he likes). Then I'll see what he wants for dinner, and just let him relax and make whatever he wants. This usually puts him in a better mood.

However, when I'm the one who upsets him, I usually get upset in response and will get pouty or pissy, depending what he was upset about. Neither of which he responds well to. At that point, we usually take some time to ourselves to stew and calm down, and then one of us will come to the other and we usually both apologize for our behaviors (it's very rare that just one of us is in the wrong). We almost always come to a resolution before bed time, though, so if he were to cut me off for 2 days I would completely melt down and flip out. But...I require a lot of communication and being cut off or given the silent treatment is the worse possible thing a significant other could do to me. Obviously not everyone feels the same.

I would think that by now he'd accept your apology and move on. If you're sorry and have no intentions of repeating that behavior, I would hope he'd be a little more forgiving. Do you know what exactly you did and how it made him feel? Perhaps showing you clearly understand what you did and why it upset him so much would make it easier for him to get over this particular issue. From what you've said, his reaction seems...well, a bit like an over reaction, so maybe you triggered an unpleasant memory for him, or something that caused an extreme reaction to a not-so extreme action.

Good luck.