I can't tell you how many posts I have read asking "is my baby weaning at 7 (to 9) months. I have even posted it myself....and my DS ended up self weaning at around 21 months (still too early for me, LOL).
At this age their little minds are so busy and they just have so many more interesting things to do than lay there and BF. My DS got to a point where he was only having one BF a day and that was when he was really tired just before bed. I just kept plugging away and offering him the breast at the normal times he would have it, he eventually went back to taking it and everything returned to normal.
Of course, everyone's situation is different, but I would suggest that this is just another developmenal stage and there is absolutely nothing for you to feel guilty about. Just keep offering and I'm sure he will start taking the breast again soon
Good luck, let us know how you go.