So basically Mary Hart is Rachel or Monica, Robert is Joey, Sue is Chandler, Takeshi and Michiko are Ross and Phoebe.
I didn’t read the whole thread so maybe someone mentioned this already.
I also hit a roadblock around Chap. 4 in Genki 1. So I just kept going on WaniKani full speed for a while and ignored Genki. Then, Koichi sent a New Years email saying how it would be good to learn Japanese in 2018. Basically, his idea was to level up to 20 in WaniKani before you start a grammar textbook. That way, you have a huge foundation in kanji and decent vocabulary before you even touch grammar.
After I did that, I started again on Genki and started flying through the chapters. Another thing I did, though, is started using an Anki deck for Genki vocab and grammatical structures. It’s the most popular one when you search Genki Anki Deck. I only use the “recall” cards because I don’t need kanji or reading practice. Producing Japanese sentences from the mind of an English speaker is what I need to work on. This Anki deck is almost more valuable than Genki itself… without it the grammar points and vocab I learned wouldn’t be anywhere near as solid as they are in my mind.
So, in short, learn a lot of kanji and vocab before you tackle grammar. That way, you don’t have to learn much new content when going through Genki. You can just focus on the way sentences are constructed.
Then, use an SRS on the vocab and grammar for Genki. It augments your success with the book by a huge margin, which is very motivating!
Good luck!