It sounds to me like you have already identified 2 different possibilities for this.

1) - stress - you just moved him

2) - hunger - he missed eating for a week

I'd suggest go ahead with your scheduled feeding and you might find that he returns to normal when his belly is full.

Even if he doesn't, it could easily be the stress of the move. Give him more time, or help speed things up by adding crumpled newspaper balls into his tank or cover all or part of the 4th side to help him feel more secure.

Also, where did you move him from and to? Is there more noise (vibrations)? More traffic? Anything else that might make the new location more stressful?