I've hurt my girlfriend

Recently, me and my girlfriend have been fighting a significant amount. It seems to be getting worse and worse. As with any fight, things are said that we regret, and it hurts the relationship. But over the course of the relationship, some very hurtful things have been said, and multiple times she has come close to attempting suicide. Today, we fought again, and the topic of her moving on to another guy came up and I flipped out and said he would probably make her want to kill herself too. But I really didn't take much time to word what I said and it came out as if I was telling her to kill herself. I really messed up this time. If there is anything I can do to make it up to her, I really want to do it. I owe her that. I can't just treat her that way and not be punished. Can anyone give me any help?

how long have you been together ? it seems that from the start this relationship seems to be one with many inherent conflictual components - since you say you've been fighting so much : what is the subject/reason for fighting ? she can not threathen you with suicide : that is putting the burden of such an act on your shoulders in an attempt to make you responsible - why would she want to commit suicide ? what exactly is making her feel bad to the point of wanting to make it stop via death ? you may know as well as I that anything hurtful is not going to help to have a good relation : maybe you both should stop saying anything that is destined to hurt - one thing you both can start by doing is stop saying "you" with pointing fingers and accusatory words - instead speak from your point of view - say : "I" feel this way - "I" think such and so - then you come from a place from self-empowering and not a draining one where all the energy goes to the other one does she think it is a solution to "move to another guy" ? that is once again a threathening act to make you want to keep her and do anything : are you willing to do anything or are you willing to respect yourself - and by doing so - respect her for respecting you ? maybe you both should take a break from the relation - give each other some air and time to ponder - and then come back - have a calm, rational and objective talk to define what it is each one of you now wants from the relation and if this is not possible for one or the other (meaning the "deal" doesn't satisfy in any way) - then part ways : it's better to part ways then stay together in a relation that tears your life apart and crumbles your well-being