IMO, what is needed is a guided approach to filling in all the holes in your foundation skills. As you have written, you are able to do certain things at the piano yet are frustrated when doing other things at the instrument. A teacher that can help bridge what you already know and fill in the gaps, lay a solid foundation, so you can go further.
As mentioned earlier in this thread, grade levels are subjective. Saying you are grade 1, does not automatically imply that you are unable to play grade 2. What you really should be focusing on is skill development. Developing skills and improving areas in which you are lacking. A better mark for progress is asking yourself, can you do something better today that you were not able to do in the past. Getting grade certificates does not automatically mean you learned what everyone else taking that grade was studying, it simply means you met the requirements of a synthetic benchmark.
If you want to improve skills, the most efficient way is to address the skill directly. For example, if you want to improve sight reading, undertake focused study in sight reading. Working on the requirements for grade 2, doesn't automatically make you a better sight reader. You can gauge your improvement by monitoring your proficiency sight reading.
If it is the structured approach to learning you are after, try to build focused learning around skill sets in which you are lacking rather than depend on grades to tell you how you measure up to a subjective average of all learners.