Anyways, I hope I managed to better express my thoughts
I'm glad you elaborated on your perspective, I found this reply a lot more interesting than your first one.
Anyways, get help from someone trained and leave us alone.
I spent 3 years trying to help that friend before jumping ship.
I think this is personally where I found issue with Shimamura's writing, though. It's one thing to get tired of trying to help someone who can't help themselves over a prolonged period of time, but... surely you wouldn't tell somebody their friendship wasn't worth bothering with the first time they came to you as a blubbering mess? I think the world would be a pretty depressing place if we could never seek emotional support from our friends in our time of need, lest we risk losing the friendship, because we didn't immediately seek therapy. That's why I perceive Shimamura to be uncharacteristically callous here. Even though it's certainly in her nature to do whatever's most convenient for her, she also usually does the bare minimum to keep the people around her satisfied too.
Others here have addressed Shimamura's apathetic personality, and I agree with them, so I'll skip reiterating what's been said on that topic.
Personally, I'd say the world is full of supportive people. I certainly was at the start. My current callous attitude stems from a rather depressing experience trying to support a friend. My "seek therapy not me" belief is because I failed. I knew my friend from the age of 11 and was friends from the age of 14. All those years together, and I failed.
Alright, enough about my own emotional baggage. Regarding Adachi and Shimamura, they haven't known each other that long, and are certainly not "close". Thus far, all attempts to close the distance have been made by Adachi, and frankly, she is a blundering fool at this, and there are reasons for that. All this, coupled with Shimamura's apathetic personality, is what drove the "you're a pain" response.