Yeah, I feel like the "take a step back and loosen up" thing works for Yomogi because of how high strung she is. But it doesn't really work for Natsumi who's on the cusp of debuting. Especially when it comes to comics, art, or whatever, the advice is always to just create stuff and in creative fields it's extremely easy for a small break to become long term. Her big problem isn't really that she's under a ton of pressure per se but that Nikaidou, as well meaning as he intends to be, has too much of a stern, old fashioned mentality so he's (intentionally or not) making her doubt herself. Which is then compounded by the personal problems like her friend's time being taken up with her new boyfriend so she feels left behind.
I feel like this would have been better as a Natsumi/Reina chapter as Reina would be good for making her realize the same sort of thing in not stressing herself so much leading to her making up with Hiro.
In general I think this is a great series and Shinzo's one of my favorite creators but there's a few instances where I don't really agree with the message or end result. Hideki quitting his job with seemingly no backup and safety net is another one. As miserable as the job was... he's got a wife and kid and should have maybe had some kind of plan first instead of having an "it'll work itself out" attitude.
I mean in regards to manga creation it's definitely the mangaka using his own experience, of course the "always work hard and keep at it to chase your dreams!" attitude is nice and all, but I'll give the benefit of the doubt to the person who has actually gone through it(ofc not saying every mangaka thinks and feels exactly the same). Sometimes it's important to step away and get a better perspective on things, you can't just mindlessly keep going at something and hoping it gets better just because "hard work!!".
Also Hideki was def gonna kill himself, like again I get where you're coming from, but the dude was gonna lose it, at that point you need some drastic measures even if it's not the smartest decision.
When it comes to this manga honestly I don't think you should expect 100% cold hard almost cynical realism, people won't always make the best decision and that's fine, that's how this manga has always been. Sometimes things work out and sometimes they don't for these characters. Also we can't forget at the end the mangaka is a person himself, he has his own set of beliefs and whatnot, so of course those will weasel themselves into his writing.