I am a 16 year old male who has been involved with a girl my age for about a year. I recently broke it off because we had been arguing.
Following the break-up, she began to cut herself and drink to get drunk often.
Her parents are oblivious to her issues and they don't realize when she is under the influence. They also have extreme tempers and will yell at her if they found out. My ex desperately wants our relationship to get back on track and is hurting herself when I turn it down. She even tried to overdose and her mom found her crying in the shower with her clothes on. She has been sent to therapy but refuses to tell the therapist anything. She only tells me her feelings because she loves me.
How can I help her without ruining my own life and without being forced back into a relationship?
If I tell her parents or older sister and she finds out, she will surely attempt suicide.
What can I do in this situation?
This is a painful and difficult situation. It's good that you seem to realize that this would be an unhealthy relationship for you, and that getting back together with her just to keep her from hurting herself would be a bad idea.
First of all, if she is in therapy - then good. She should be. Regardless of what she may be telling you about not telling her therapist anything, it's possible that she actually is talking to her therapist -- but is manipulating you to try to get you back, by leading you to believe that you are the only one she can trust. (Just a possibility).
If at all possible, it may be good for her to use a suicide hotline (confidential - 24/7 helpline) so that you aren't functioning as her crisis line. Of course you can't force her to use it, but you could suggest it (1-800-SUICIDE).
Her own family is far better positioned to intervene to keep her safe, than you are. If you don't feel comfortable breaking her confidence and telling her parents, maybe her older sister is a safer person to get involved in this. Lastly, you could make an anonymous call to her therapist and share your concerns.
It's also important to understand that "cutting" is not necessarily the same as being suicidal, although it is certainly a danger sign and a clear message that she is in deep emotional pain. Cutting can be very addictive as a coping mechanism and definitely needs to be addressed by her therapist, but not all people who cut on themselves are suicidal. They usually cut their skin to relieve emotional pain or to "feel" themselves, when they are feeling emotionally numb.
I really can't advise you here. It's your decision. I've seen many people use threats of suicide to try to get what they want - especially when heartbroken after a breakup - but at the same time, you have to take someone seriously if they are talking about suicide. In the most serious circumstances if you ever believe she's about to seriously harm herself, or is threatening to, you can call 911 or the police to intervene.
Chances are, any attempt you make to be a friend to her is just going to cause her more pain, if she wants you back as her boyfriend. So while you think you are being emotionally supportive, you may just be reminding her that she can't really have you. In the end, you may need to distance yourself -- but that's not a choice anyone else can make for you.
You have to take care of your own feelings, and boundaries, and be careful not to get caught in the role of rescuer. Involving others in that role might help take some of the burden off of you.