This happens to me about once each year so far. I get into a period of realizing that just when I thought I was starting to get a good understanding of 'what it is I am supposed to be doing'... I go to seminar and learn something 'different' about it or my own Sensei shows another aspect of it and I find myself back to square one feeling like 'I cannot understand and make it work' and 'will I ever make it work' and then... I remember... just relax and have fun with it.. hopefully many more years to enjoy the training and the rest of my life in exploring it and so things get better and I feel like I have learned how 'simple' it all really is.. just not 'easy'.
I always teach that aikido is a lasagna. There are many layers.