To the original poster: could you talk with your teacher about this? Could be that he or she sees that you are progressing nicely, and doesn't realize that you are feeling frustrated at the same time and in need of more challenge.
Have you visited the other available dojo in the area? That might be a good idea to do even if you're not planning to change. You might just happen to visit a dojo that is a great fit. Or if it turns out that they are all terrible, at least then you know that you've made the best choice you can.
There are things that you can focus on in practice that aren't dependent on who you partner with. For example making sure that you're always standing and moving in a balanced way is a very useful thing to focus on in the first years of practice. Or for example staying as relaxed as you can even if your partner is stiff. Doing a teachnique while at the same time staying aware of your surroundings.
Maybe other people have more ideas.