You are not a bother. Doing what we can to help is what this service is for.
It sounds to me like you’re right. Your mother is suffering from depression. The blaming and criticizing and cursing isn’t really about you. It’s about her frustration and emotional pain. She has reason to be depressed and irritable. She has lost her partner and her health. She is probably more dependent than she ever imagined she would be. After years of maintaining a positive attitude, she’s exhausted. That doesn’t make it okay for her to be critical and rude to you. But maybe it helps you to be reminded that she is tired, not terrible.
At 19, you are in a position to be helpful. Part of moving into adulthood is to see parents as people and to shift from being a needy child to being a supportive adult. Right now, you are the one who can change your relationship. Your mother can’t. She’s too locked into her depression. The first step is to stop trying to change her. You can’t. The only person you can change is you. If you do, it is likely she will eventually start to shift as well.
A person can only be in an argument if the other person argues. It’s time for you to stop. If your mother says something hurtful, just say something like “I’m sorry you feel that way” and excuse yourself. If she blames you, don’t get defensive. Remember it’s not about you. Just say something like, “I know. Things are hard.” Find out what resources are available to provide her with counseling and some practical help and offer her the information. If she pushes it away, just leave the information where she can access it. Don’t insist on it. Don’t be pushy. Just tell her you love her and want better for her.
Do reassure her of your love and admiration regularly. Just don’t get hooked into debates. Bring her water. Offer to do her hair or polish her nails. As soon as she goes negative, say something like “I guess you’re too tired. I’ll come back later when you feel better.” No sarcasm, please. Smile. Give her a kiss and leave. Check back in after an hour or so to try again.
Meanwhile: It’s time for you to get on with your adult life. You didn’t mention whether you have a job. I hope so. If that’s not possible, start volunteering at something meaningful to get you out of the house and to build your resume. Join an activity where there are other young people who share your interests. Your mother can’t offer you a whole lot of support right now so you need friends who can.
Right now, the only “person” who is winning in your home is Mr. Depression. Don’t let that continue. Kick him out the door and resolve to bring back the beautiful attitude your mother once provided. Once there is more love and light in your relationship, your mother may be more willing to accept the help she needs.
I wish you well.