First off, there is nothing you can do to help your mom. You mom doesn't want help, at least not right now. The only thing you can do is protect yourself as best as possible.
Did you file a police report after she assaulted you? I know it sounds harsh, but if you really want to help your mom, she's going to need to hit rock bottom. Protecting her from her own behavior will not help her, that's called 'enabling'.
The fact that she's tried to commit suicide means she's either hitting rock bottom and has no idea where to turn, or she's truly that depressed. Getting the authorities involved might actually HELP your mom. For one, when in jail, she won't be able to drink. For another, the courts may require her to go to AA or into rehab.
If she doesn't stop drinking it is NOT your fault. You do not force her to drink, you do not buy it for her or pour it down her throat.
If she commits suicide, that is also NOT your fault. Your mother is damaged (as well all are to one extent or another), and she may simply not be able to handle the world anymore. But her damage did not come from you.
This is a situation which is largely out of your control. If you can come to peace with that, you may be able to save yourself a lot of damage to you.
As for filing a police report and pressing charges, it would take a tremendous amount of courage to do that. I would totally understand if you didn't. But...if you did, here's a framework to think about: you are doing this not to be spiteful or mean or vindictive, you are doing it because you love your mom and you're scared for her. You are doing it not to punish her, but hopefully to force her to get help. As long as your actions come from a place of love, and not from a place of fear or meanness, then you're on the right track, no matter what she says to you.
We're here to support each other. Everyone posting on this board is here for a reason, and many of them are very similar.
Your mothers behavior does not strike me as unbelievable at all. It strikes me as the desperate acts of a desperate woman who feels she has nothing left to lose.
The best you can do is protect yourself emotionally (and physically), and accept that her damage is not your damage, that you did not cause it, and that you are powerless over it.
I am so sorry to hear you're going through this.