Anger and guilt are normal feelings and so difficult to come to terms with,I have no doubt you did your best to help and thats all any of us can do but every one of us here has probably at some point found a reason to feel guilty under all the circumstances suround losing our loved one, because this cruel journey makes us think like that could we have said or done something different and changed it, in truth the answer is no, because we dont have that kind of forsight, if we had said or done the opposite, the outcome would probably have been the same and then we would be asking ourselves should we have done/said what we actually did instead and so the circle of bus and maybe goes round and round..
Depression is a beast which surounds people, i had a close friend who did the same and questioned did i do enough, even though i did everything i could think of at the time, he simply hid his intention better, even to the point of laying a false trail so we all looked in the wrong places for him. We cant get past it to reach them and pull them out of those dark clouds, but i,m sure they know we try, and we are there for them and love them, even through that hell they are living in.