How important and how powerful are you willing to believe yourself to be?
Are you more powerful and important than the boyfriend? Are you more powerful and important than this guy's concern with his own pain? Was his pain that trivial? Are you more important and powerful than the man's drive toward life and survival?
It may be that you are any and perhaps all of these things, but the more likely answer is that you wish you were more important to the guy than he was to himself.
At that point, what were you going to do with him?
He needed somebody at every moment of every day to edege him into being able to caring for himself. Your attention is not well developed enough for that, though you may wish it were. You can't even concentrate on one thing for an hour, if you're like most people.
If you're going to concentrate on one thing for an hour, and that one thing is going to help you and the other people around you, learn to concentrate on your tummy. Learn to notice if it is rising or falling. Notice when you inhale, that it is rising, and then say in your mind, "rising." Notice when it is falling that you are exhaling, and say silently in you mind, "falling."
If you are starting to think about your friend's suicide, say to yourself, "whoops," and gently bring your attention back to your breathing. Don't do more than about an hour of this a day.
If you're thinking about your friend's suicide, you might say to yourself "thinking" or something of the sort, to let yourself know that you're really not taking care of business. Your business is to make your mind work in an orderly straightforward fashion. You already know you aren't powerful enough to bring your friend back. You already know that you did what you could to deal with your friend while he was here. If you want to learn how to do more, then you must learn how to make you mind work in a concentrated and orderly fashion. This is the place to start.
If you are sad, then you are sad. Notice your sadness and then get back to your breathing while you are meditating. First things first. Do your laundry when it's time for laundry. Make sure the dishes are clean. Sweep the floors. First you eat, then you sleep. Work when you need to work, and love the people that you love. Sadness comes and goes, but self torture is something that is not necessary. Sadness is difficult enough. Why substitute when sadness is so unique and natural. We don't have to hold on to it; it will come again, and not always predictably.
That is why it is so difficult to give up self-torture.