I would try distancing yourself from her and listen to some music? Do you have anyone that you could join a bingo group with or a book club in your area or something to distract you. Please also talk to a doctor.

It's hard to get such hateful words out of your head when they come from someone who is supposed to love you. I would take it as a challenge to live in spite of her. As they say, living well is the best revenge.

That's not a challenge to kill yourself.

That's a challenge to live.

She's telling you to pull your head out of your proverbial. Can you not see that? She's had a gustful of you. Why? What is pissing her off about you? And do you talk about killing yourself a fair bit?

She's had enough of you. Sounds to me like the modern caring 'oh don't do that' hasn't worked for her so she has returned to the classical 'there's a tree, here's a rope, knock yourself out' response that I would expect to receive from my mother.

So time to get off the pot really, and live. Get up and live.

Horrible thing to say but yes as Bridgie said she may have had enough and believe that her words, even if they're harsh dont matter anymore. I have many phrases as well from people that somehow just stick in your mind, mostly due to them being judgemental and me trying to meet the expectations of dickheads. But your phase from your mother is cruel and hurtful.

Horrible... It does sound like she's "daring" you to do it, I've had the same thing done to me by a parent as well so I know how much it hurts. This is just your chance to prove yourself though. Don't let it get to you, I know it's hard to get certain memories out of being constantly on your mind but it happens with enough time.

I'd get angry, then obsess about something else, get to work on a creative project, spite my mother by outliving her.

I can't believe your own mom said that to you!!!! I am in shock. I don't think anyone would be able to get that thought out of their minds! I'm sorry. I don't mean to overreact. I just think that's awful.

Not a nice thing indeed, I think the best thing is to either immerse yourself in a hobby if you have the inner strength. Meditation could get you around this as well although it isn't easy to do at the best of times, YouTube has some good guided ones which will help most anyone to get through intrusive thoughts.
If you ended up doing it, she would be beside herself with guilt...no one should say that to a person struggling. Sure hope you can get the thought out of your head soon.