Don't get discouraged that you feel you haven't improved! The biggest reason why you feel you haven't improved is probably because you don't fully understand a concept well and in that state you are repeating the same mistakes.

Maybe try re-doing some excercises from Lesson 1 and watching/reading the instructions closely. For me it took about 2 or 3 times to fully understand certain concepts(like rotating a box) and even more repetition to get it right.

This a journey and it's bound to have some bumps in the road. Use the time to reflect on the mistakes who might've made and learn from it.

Hope this helped a bit! You can do it!