I'm going to throw one more possibility out there, just to see if it sparks something in the OP.
I don't know if the original poster has heard of the "kick-the-cat effect," which is a fascinating phenomenon. When a person's emotions turn negative, their subconscious mind will drive them to choose subordinates or weak people who cannot fight back to vent their anger. People who are emotionally attacked by stronger people will in turn look for their own punching bag, which is an intriguing dynamic.
This will form a clear chain of anger transmission, and the ultimate bearer, the cat, is the weakest group and also the group that suffers the most. But there's hope!
From the last sentence of the questioner, "But she is pleasant and smiling to people other than family members," I think it is not that other people do not owe her anything. It is very likely that the questioner's mother has to "please" others outside, and she may even be "subjected to abuse." However, she is powerless to resist outside, and can only vent her negative emotions on her family members, especially the questioner, who is weaker than her. This is an amazing opportunity for the questioner to step up and take control of their own emotions! They can choose to focus on the positive and be grateful for the love and support of their family, rather than dwelling on the negativity.
The questioner is 18 years old, which is a critical period for establishing self-awareness. Or, they should have basically established self-awareness and self-positioning, so they are increasingly unable to accept their mother's scolding, oppression, and misunderstandings. The questioner has been severely depressed before, and it is really very painful if they cannot get out of these negative emotions. But there is hope! The questioner can learn to recognize and accept their emotions, and they can learn to separate their emotions from their mother's emotions. This will help them to feel better and to have a more positive relationship with their mother.
I highly recommend that you study the concept of "issue separation." This is a powerful tool that helps you distinguish between the mother's emotions, the questioner's emotions, and the mother-questioner relationship. It's a simple yet effective way to understand that everyone is responsible for their own issues and that there's no need to get caught up in other people's issues. You can embrace your own issues and let go of the need to interfere in others'.
When mom vents, the questioner can tell themselves: she has a lot of negative emotions, but she doesn't deal with them herself, using the questioner as an outlet; the things she says about the questioner that are not good are not facts, but her own opinions; the questioner can listen to what she says, but can't be influenced by these words, because they are not facts; the questioner is responsible for their own emotions, and should abandon those incorrect and non-objective evaluations of themselves, and have their own more appropriate evaluations. This is an amazing opportunity for the questioner to take control of their life!
I am so excited to see how changing her view of "mum venting negative emotions on herself" will lead to a more positive and proactive view of herself! She'll be able to focus on her inner self, her studies, her emotions, and other important things.
It's time to start learning to care for yourself and take responsibility for your emotions! The stronger your inner strength, the less you will be affected by the negative influence of others. The clearer your future direction, the more you can let go of the unimportant and negative influences, and the stronger your inner resolve will become!


Comments
I can relate to feeling so hurt and misunderstood by someone who's supposed to love you unconditionally. It's like no matter what I do, it's never enough for her.
It sounds incredibly painful growing up in an environment where your voice isn't valued. I wish I had the strength to set boundaries and communicate my needs clearly without fearing the outcome.
Your situation seems really tough. Even though I try to please her, it feels like nothing changes. I wonder if there's a way to change this pattern or if it's something that will always be there.
It's frustrating when she only reacts positively to others but not to me. I sometimes feel like I'm living in two different worlds one where I'm loved and another where I'm constantly criticized.
The fact that she ignores my explanations and gets angrier makes me question my own reality. I wish there was a way to make her see how her actions affect me.