ask for help for yourself. I have had a friend that did this, and the only advice that I can offer is that it's different for everyone. Please do not take this on yourself, it is NOT your responsibility to ensure that SWIM stays alive. I know that it may feel like that, but it isn't. Asking for help for your own feelings is important too, to help you to deal with the pressure that this is putting on you. I never got any help after my friend was self-harming and it has affected me in countless ways. Please try and speak to someone about how you feel aswell as trying to get help for your friend. And try not to worry too much, at this point your friend has already seen a doctor and has asked for help, which is one of the main steps to actually getting help.
I hope everything turns out ok.