I am not sure how experienced you grade 8 teacher is. Grades are not the only measure of musical proficiency. IMO, Beethoven sonatas are seriously challenging musically and for a large majority challenging technically. Movt 3 of pathetique requires very clean articulation of the notes and clear musical phrasing with proper direction. Also in this case you also have to bring out the character of the rondo out. In addition, there are many subtle nuances in the entire piece that requires proper understanding and execution to bring out the rondo's character.
Your teacher is not qualified if he just go through the techniques solely (though the 3rd movt is not really that technically difficult). He should also be guiding you on how to express the musical line and to help you gain authority over the direction of the musical phrasing. He should also be aware of the execution of the various phrases and their styles so as to bring out the best effect. Finally, he should also give you the feeling of mastery and freedom of expression over the entire piece.
If you don't really feel satisfied with your musical progress I strongly suggest you to get a better teacher preferably with at least a music degree in performance majoring in piano.