You've identified the dgf and dgm elephants 
What happened to you when you were 20 was not properly or fully addressed at the time and it was subsequently compounded by the years of abuse you suffered at the hands of your ex which may have caused you to believe that you were worthless, or that in some way you attracted abuse because it was no more than you deserved.
During the years since you left your ex you may have begun to emerge from the fog of negative thinking and then up pops the harbinger of doom on FB shortly followed by the heinous crime which was perpetrated against you last November, the net result of which has been to freeze frame you in both the distant and recent past by causing you to suffer from PTSD.
The 'justice' you sought but, unfortunately, haven't been able to achieve is not simply a case of bringing one offender to account as all three of those males who abused and used you for their own ends should be standing in the dock and, imo, this is why you are finding it so hard to come to terms with the decision that has been made in respect of the one offence you have reported to the police.
What you would benefit from is a surfeit of TLC of the type you would give to your dc if they were feeling poorly, but as adults the onus is on us to administer self-care as and when we can while continuing to spin all of those plates which are necessary to keep a roof over our heads and food on the table while fulfilling all of our other responsibilities/obligations.
If we were to meet in rl I would at least be able to give you a hug, hold your hands, look you in the eye, and tell you that NONE OF THIS IS YOUR FAULT and we could proceed to get hammered debate why some appear to get all the luck and so many either don't seem to get any at all, or the little luck they do get is shortlived.
The objective of any such debate would be to persuade both of us that there may be some underlying reason unknown to humankind why our lives pan out as they do and that, even when we may feel that we've been run over by a steamroller or have been broken into a thousand pieces by the cruelty of others, we can pick ourselves up and carry on to the natural end of this sometimes frustrating but fascinating journey called life - and more importantly that, no matter what happens, we can create or regain a zest for living that we may have come to believe is way beyond our capability.
As it is, all I can do is to entreat you to put aside any thoughts of suicide and focus your attention on the need for you to source all of the help available which can enable you to heal the hurts and harms that have been done to you and move forward with confidence that, no matter what the future may hold, you WILL survive because, regardless of whatever else you may be, you ARE a survivor.
get out and smell some today, honey, and why not treat yourself to a bunch?