You have lost the love of your life, and now you want to win your boyfriend back. Maybe you have made mistakes and so has he, but you have realized how blessed you were now, and it seems to be too late, or is it?
Take a deep breath and be YOU. If you are normally sweet and loving, remain that way. You may have every emotion filling your body, anger sadness and hurt and you are very desperate to win him back, and without a second thought you scream and threaten him. This will not help get him back. Screaming at him will push him away and make it easier for him to get on with his life. Think about this for a moment. If you were in shoes and someone was being mean, you would think you made the right choice by leaving. However, if someone is being sweet and loving, it is harder to leave.
Do not be clingy. Your first impulse will be to call him constantly, or try to see him. Try not to. This will push him away as well. You can be a mess behind closed doors, by all means, talk with family and girlfriends and share your pain. Break up can be a hurt like no other, and sometimes getting through each day seems impossible. Take things one minute, one hour at a time.
Understand if you do not win your boyfriend back, life will go on. You alone are enough. You do not need someone to complete you. You are amazing and loving and have such a huge heart, he is the one missing out. If he can not see your beauty inside and out, trust me, someone else will. Maybe he isn't the right one for you. If this breakup doesn't happen, maybe the soon to be "Love of your life" will not be able to enter your life, because Mr. Wong is still with you.
Follow all the above advise and pray for the best. Be ok with whatever may happen and know you will get through anything, and become stronger because of it.