I am truly saddened that yet one more person has made the choice to end their own life. Under no circumstances are you responsible for their choice just because you asked a direct question. UNDER NO CIRCUMSTANCES are you responsible - I typed this twice in the hope that you will take that statement as Truth and release yourself from any guilt that you may be associating with this person's choice.
Having said that, you are entering into a realm of complete emotional horror that requires a trained and qualified guide to help you set your feet firmly onto your own healing path. Past events, and this most recent development, are the proverbial millstones around your neck that will prevent you from moving forward and processing the episodes without causing harm to yourself and, especially, others. Left unattended by a trained and qualified professional, these issues will taint every decision that you make for the rest of your life. Time for some strong, tough, and distasteful medicine. Yes, it is possible to successfully process all of this on your own and alter the course of your emotional life, but it's a long, long, lonely hike down that particular path and many, many roadblocks stand in the way of positive and meaningful growth without the assistance of a qualified person to help present as many options as possible. Yes, trust will be an issue, but you've opened up on this public forum, so you obviously have the desire to deal with all of this.
As for attending this person's funeral, that has to be your own personal decision. Was this person someone who was valuable to you, or are you only able to associate this person with ugly past events? Keep in mind that a funeral/memorial service of a successful suicide is not pleasant, under any circumstances - it is ugly, it is emotionally draining, it is hopeless, it presents a sadness that is so complete that it defies description, and it consumes portions of the survivors' souls if they are not strong in their own skins. There would be nothing positive about this event, in my most humble opinion.
You've had some personal epiphanies and learned some very tragic news. Now, it's up to you as to how you're going to manage all of these issues. If you wisely seek professional help - that is, assistance in processing and moving forward - you can find a good, strong counselor by contacting your local "mental health" hotline and asking for the names of a couple of counselor/therapists that are familiar with sexua| abuse and Post Traumatic Stress Syndrome. If you don't have insurance coverage to pay for counseling, most counselors (or their clinics) will work with you on ways and means to pay. If you are unable to pay, there are qualified counselors out there that work through Social Services, and you can contact that agency if it's necessary. I would strongly urge that you remain cautious of using medications - medications may help on a short-termed basis, but they often only dull the normal human responses and, guess what? Once the medications are gone, the episode(s) and its aftermath remain. This includes self-medication.
From your posts, you sound strong enough and willing enough to Do-Something-To-Save-Your-Self. Don't hesitate. Take this most recent event as a direct indication that you have a choice that requires immediate attention: a> save yourself and become the human being that you were meant to be, or b> do nothing and remain a part of the cycle.
Please, for your own sake, get some help for yourself. I wish you the very, very best.