Firstly, whatever has happened, it was because both of you were at fault. If it was you who cheated, you did it because you were not getting what you wanted from your partner. If it’s your partner who cheated, it’s because you were not giving them what they needed. The person who got cheated might not be morally responsible, but in the end both of you have an equal share.
As it is important to forgive and forget in every relationship, so is it for love. It’s not possible to get the person back if you can’t truly forgive them. Forgiveness means you forget all the hard feelings relating to the particular incident and never bring them back again into the relationship.
If you were the one at fault, apologize. It’s not just an apology for the sake of apologizing but you must mean it. Once you say you are sorry for something, feel truly sorry and never do it again. Many times people say a sorry and there would be again a situation that it’s repeated. Most of the times after an apology there would be a situation where they do the same mistake again. Watch out for such mistakes.
Be prepared to chase him, though it doesn’t mean going around where ever they go or bug them up with messages and mails. Don’t expect him to consider your apology or fly back to you as soon as you apologize. You need to gain his confidence that you still need him. In order to achieve this, keep your heart in line before your ego.
If the guy is willing to settle for friendship instead of a boyfriend, for a short time of course, you might have to take the modest. It may take some time for him to get that trust and fully commit to you. In such cases you need to give him some space and time as well to settle with the new relationship.
And in the end, you must know when to stop struggling over a lost relationship. If your ex is not willing to forgive you, it’s no use clinging to him. It’s important you get over your dream and get going with a new relationship. It may seem hard for the moment but that’s all you can do. Whatever was the matter, he was not the one for you and your better half is out there waiting for you.