I generally don’t post here at all, and I’m not a parent, but I think I have a valuable perspective (mods, let me know if I shouldn’t be here/post this somewhere else). I’m a current student at a T5 school and dealt with pretty severe clinical depression in high school. I had pretty similar symptoms to your daughter- my (also asian lmao) parents will tell you I didn’t talk to them, I didn’t talk to my friends, I cried all the time, I slept too much, I didn’t come out of my room, etc. When you’re in that state, it’s really hard to reach out to people and really really hard to believe it’s going to get better. I had been doing okay academically and with my extracurriculars (probably helped partially by the fact that this was pandemic time) but I was also very profoundly unhappy.
Just based on the symptoms you listed, it sounds like your daughter is legitimately depressed. You can do one of the screening tests online, the HAM-D is fairly reliable, but it’s pretty unlikely that she’s been dull and unhappy for no reason. So at least check it out. Like some other commenters have said, I would completely back off from the topic of college admissions. It’s possible that it was caused by stress, but the fact is that there are a lot of risk factors for depression/anxiety (of which a period of high stress is one) and you might never know “why”.
I can tell you some things that helped for me, and you can show this to your daughter if that helps. If she doesn’t want to go to a therapist, then you can’t really make her go to a therapist- therapy against someone’s will basically doesn’t help at all [can cite studies on this if you’re interested]. However, I know that there’s a big stigma against it sometimes- especially in the head of someone that’s depressed- that there’s something wrong with you, or that the therapist is going to tell your parents everything, or that you’re lazy. It’s usually not like that. They have very strict privacy policies. Sometimes it’s just nice to have someone to talk to. And like I said, when you’re in that mode, it’s really hard to believe anything will help.
If she doesn’t want to go to a therapist or doesn’t have the energy, meds are also an option. You should talk to your PCP or a psychiatrist about this, although psychiatrists (and therapists now, unfortunately) have long wait times. Modern SSRIs are very safe with well-known side effects and sometimes they really do help. Regardless of this, the average length of a depressive episode is six months, so about half of everyone will recover in this amount of time anyway. Don’t leave it to that, though.
Other than the obvious meds/therapy options, there are other things that help. Encourage your daughter to meet her friends/do things that make her happy. If she has a poor sleep schedule, often it really helps to fix that (circadian rhythm and depression are linked in weird ways we still don’t understand). If she’s not eating regularly, that’s important too. Same with exercise.
Unfortunately, as a parent, if you say these things it can sometimes come off as you not believing it’s “real” or that she’s being lazy. (I remember I felt like my parents didn’t really “get” my depression, maybe because as Asian Americans there’s a big stigma.) None of these will solve the problem, but all of them help a little. Behavioural activation is another big thing- it helps to go outside, to do fun things, to listen to happy music, to do hobbies. (Probably all of this is blindingly obvious to you but I’m saying it for completeness). The last thing I will say is that if your daughter has been expressing both suicidal thoughts and the intent to seriously harm herself you should go to the hospital immediately. Other than that inpatient care usually doesn’t help.
I guess the good news is that it does genuinely get better, and there are ways to help. College is so much better than high school was for me. I sleep more than I ever did in HS. I have a lot more closer friends, and maybe surprisingly for a T5 school, a better relationship with work and stress. There’s a lot more freedom and less pressure to compare yourself with other people.
Feel free to ask any more specific questions or contact me directly. Thanks and good luck.