It's always a distressing moment when your relationship gets into difficulty, your boyfriend or girlfriend decides that a long-term commitment is now no longer what they want. It can look like the end of the earth, but there a few basic steps that you could take to try and prove to that loved individual that the relationship is worth saving, and that you're prepared to step mountains to rescue it.
Communication is a fundamentally important part of any relationship, whether it's a rosy one, or whether it is one that is on the brink of ending. Talk constructively, discuss your grievances and concerns, and try and make use of these discussions as a foundation to go forward within the relationship. It is fundamental to keeping your relationship together, or parting on civil terms.
Though when things are tense, talking and listening effectively can be very hard. Do not take an antagonistic approach and tell your other half all the things that they did wrong. This will cause further problems and make resolution of the issues nigh on hopeless. Say what you need to say in a calm and gentle voice, and listen to what your partner has to say. Don't just stare out of the window as they talk, pay attention and be seen to be taking in everything they say. And even if your pride is hurt don't disagree with everything they say just for the sake of it. There will be points that they make, that if you are honest with yourself you will have to agree with. If you can be seen to be doing this they, while possibly tremendously hurt, will see if you as a person who is up to taking responsibility for their actions. And with any luck they will do the same.
When a relationship is in a difficult stage, the last thing your partner will need is to be hassled and made to feel they have no freedom to move. That claustrophobic sensation when a loved one is constantly bothering you does not put one in a position where they desire to kiss and make up. So grant your partner some space, give them all the space they want, but be seen to be there for them if and when they want you.
Be honest about the things in your relationship that have caused it to come to this hard moment. Truth is a wonderful thing, but at times you need to consider how you word your grievances so as not to put a harmful bias on it. If there's something you want to say you should say it, but do try to work in a way that does not make your partner feel wounded, angry or worthless.
These are several very simple strategies that one could apply all through one's life and in one's relationships, but they are acutely important when you are trying to salvage a relationship that is in difficulty. Ideally use them before it gets that far, but if you're in the 'last chance saloon' you have got little to lose but try. Good luck and I hope everything works out well for you.