I totally agree with the previous posters...
One thing that I did try to do to minimize the amount of time I spent away from Bella was schedule my classes relatively early and back to back. This way I was able to go to class...study directly after class...and then get back home to Bella. I also tried to have consistency with my scheduling (ie I left for class at about the same time and returned home at the same time - or as close as possible) so that she was able to remain on a pretty decent schedule.
I also spent a lot of time taking her on walks. And whenever I would study or visit friends she would go with me (stealing all of the attention of course
).
I hope all goes well for you this semester!
