1. If he wants to leave, let him walk. You can’t force feelings on someone who doesn’t have them. If his feelings have changed you pressuring him and trying to show him how much you love him will only push him away further and faster. If he wants to leave, let him leave and let him live with his regret or find someone better. And you do the same.
2. He will do the thing again. Whatever he did that is causing tension, maybe it was cheating or going behind your back, he will do that thing again. He might apologize, but an apology means so little because people break their promises so often.
3. You become the friend everyone hates. You turn into the friend who only comes around when she has relationship problems and the whole time she just talks about the problems that no one wants to hear about. It’s not fun and no one likes that friend, they just feel bad to completely cut her out.
4. You lose your self-respect. If he messes up and you’re still fighting for him it makes you look bad and gives you a bad reputation. People will start to see that you don’t respect yourself by continuing to fight for someone who clearly doesn’t respect you.
5. The trust is gone. If you can’t have a functioning relationship without fights and arguments over nearly everything you surely can’t trust each other, and without trust you have nothing.
6. Don’t fight for him because you’re scared to be alone. Don’t convince yourself things will work out because if they don’t work out with him then you’ll forever be alone. You won’t be alone; you will find someone else because he was clearly not your forever person if he’s hurting you this way.
7. He will resent you. He will start getting angry at you and get fed up every time you try to do anything. You can’t smoother someone and expect it to work because it will only push them away further. Don’t make him hate you. You can’t turn a person into a person they’re not.
8. It’s too late. Your relationship might have hit a dead end a while ago and you’re too blind to see it right now. You can’t make someone stay when all they want is to leave. The beginning of the relationship was probably the best, but since then it just faded and you can’t seem to get it back. It’s because you’re not meant to be together, just let it go.
9. He needs to discover himself without you. He might be going though something personal and he just needs time alone to think. He might need growth and change, but with you he felt that was being restricted. Let him go and if it’s meant to be he will come back.
10. You need to discover yourself, too. This isn’t all about him, you need to do some soul searching, too. You need to feel the pain of him leaving and decide how you’re going to pick yourself up and heal. Out of everyone who comes and goes in life you’re truly the only person who is always going to be there for yourself, so you better start working on that relationship.
11. You can’t force someone to change. You can’t turn them into someone they’re not and make them love you when they don’t. If he has bad habits you can’t stand he probably won’t stop for you because those are things he needs to work on himself. He can say he will stop or won’t do it again, but saying and doing are two completely different things.
12. His friends will think you’re a psycho. Every time his phone rings and he’s around his friends they see the expressions on his face. Guys talk , just like girls, they know what is going on and it will make you look like a crazy person. Looking like he’s dating a crazy person in front of his friends will only push him away further. Don’t be that girl who is blowing up his phone.
I know this might be harsh, but you can’t force someone to be there and you can’t force someone to love you. Let him go and if he comes back then it’s meant to be. 
