Two hours of practice a day for months, and you barely improved? Look back a year instead of a week.

Improvement happens too slowly to see at close range. Week to week you are comparing yourself with yesterday, which is the one comparison guaranteed to show nothing, and so you conclude the work is not working. The gap only becomes obvious across a year, because a year is the timescale the body and the brain actually use.

Find a video, a test or a time from about a year ago and look at it properly. Note one thing you can now do that you genuinely could not do then. Keep a short monthly record so next year’s version of this question already has an answer.