I'm thinking of cutting out a suicidal friend from my life
Are you really gonna cut him out of your life?
Yes, I'm having trouble coping with him.
I understand your position, but it's not right to abandon a friend in his time of need. You ought to help him any way you can.
I'm worried that he's going to trigger me.
While you really should be there for your friend, it's understandable to end things if his suicidal ideations are negatively affecting you. It's not a good idea to maintain a relationship with somebody who's behavior is hurtful toward you. Just be sure to end the friendship in a way that won't trigger either of you.