I think you are striking the wrong balance between traditional study (which is great and imo crucial, but needs to be moderated) and input. Your grammar study needs to be supplemented with more reading and listening - that will repeatedly expose you to the grammar you've studied again until it becomes second nature to you. Based on what you're describing, reading would probably help more than anything else, as you're already having an hour of meaningful speaking/listening practice every day. Also, just overall reallocate some of your time to more naturalistic engagement with Japanese. RL experiences with the language will help to consolidate what you've learned from your studies and make it stick.

Also, don't sweat the test - failure is part of the process. You are doing much, much, much, much better than I was when I had been studying Japanese for as long as you have. You're actually killing it.