Yeah sorry didn't want to knock you spirit. I did the same thing at first thinking that it was fairly easy.
You will benefit from more pull ups in the ratio and hopefully you will find that helps you to progress to full pull ups.
I myself tried a few differing pull up substitutions sticking in the end with negatives and body rows. I progressed my body rows using rings on my pull up bar like these
lowering until I got horizontal basically on the floor. I kept on with these for a while until I could do pull ups on D2 and D3. eventually leveling up. Even after leveling up I stuck with horizontal body rows on D1 for a while to reduce impact on my elbows but with time I moved over to all pull ups.
Good luck with what ever you choose to do. But, why not stick with the way you are until next week, at least you will see what your Friday progression is compared to last week. Progress is the one thing that keeps me going on this when I struggle it is so important to the program.
You can then start fresh on Day 1 next week!
Again Good luck!