I agree, the conversation about the tumor could have been a misunderstanding.
I have had friends that "played" the suicide card with me and I do not think that is fair or right. I believe that someone that is truly suicidal would not threaten all the time, sadly they would do it!
I find that kind of a manipulation!
If you are out with this friend and they stick up for you for whatever reason that is one thing but to text people and tell them off kind of sends the message that they have to take care of you! I don't think that is a good idea.
This person does sound like they care, but maybe they play games!