Aikido training can be really, really frustrating.
I've coached many beginners, and many parents of younger beginners, that Aikido is different than most other martial arts, in that the learning is considerably less linear. I think that this nonlinearity is one of the two or three key factors that contributes to the very high rate of attrition, especially early on in our training.
But, it occurred to me in class today that learning non-linearly doesn't necessarily mean learning more slowly. It's just harder to measure progress.
Remember that when we train in Aikido, we usually do it in some sort of set form, or choreography. We work on some particular technique, the way Sensei is showing it. This is, of course, partially because we trust that Sensei knows what they're doing. But it is also simply a way of focusing the class, so that we can train together. Any given technique may not ultimately, eventually, work for you exactly the way it's being shown in every situation or with every Uke. When you find yourself frustrated by not being able to make your technique look like Sensei's technique, rest assured that, in the long run, that isn't really the point. Ultimately, eventually, your technique will look like your technique.
So. Keep trying to do what Sensei is showing. Keep your mind open. Just be aware that, even if your technique does it look like Sensei's, it doesn't mean you are not learning anything! Someday in your training, the things you're not even aware you're learning will come through.
I once had a teacher tell me "Aikido isn't something you try to get better at." What he meant by that was that you simply need to keep doing it.
Domo Arigato