How can one let go of unwanted memories?

In life, there are some memories we want to keep it forever, however there are some which is not that happy that we would want to forget. The question is how can one forget or I should put it "How Can One Let Go of the Memory He/She Doesn't Want?"
Does it involve mask? Hiding your true self when it come to facing that problem?orAllowing yourself to continue getting hurt for the time being till one day (don't know when it'll come)?orJust say what you feel without caring about the other party's feeling (burden/stress)?
The main question of mine is also related to "Do you prefer to hurt yourself or to hurt someone you love?" How can this be answered?Stingy people who cares for themselves will answer they are the most important thing. However, for those who is caring (I doubt so whomever out there is like that) will choose to sacrifies themself.
Relates back to my previous post, "Life", we are full of choices to make everyday. If you were to let go, you have this kind of ending. However, what if you choose the other one? No one will ever know the answer because each one of us has different life and we live our life differently from another person. So the experiences that we are going through daily is different. So the other road that is not chosen is something where one can fantasize however they like and regret on this very road that they have choosen and is walking on currently..
Another point where one can lose an unwanted memory purposely and it can be accidently is through serious accident that involves brain. Lost of memory would be the best because those memories will not haunt you and you can totally start a brand new life.. The 3 suggestions that I have mentioned will never work for the rest of your life, as long as you live.. Memories can never be erase.. Time cannot be turned back.. Mistakes cannot be undone.. Water that has been poured away can never be collected back..

I'm still lost...

6 months of being away from you has past.. It is time to face you.. Face the fact and reality.. I'm still lost.. Till now, I still don't know how I want to face you.. Acting behind you, I have no problem. Since crying in this end you cannot see.. At least this wouldn't make you difficult. But.. I'm still tryiing my best to think andto find the easiest and fastest way to forget you.. Unfortunately.. I failed again..

For the past 2 months, I've been telling people I'm ok.. I can go on without you and you are not a problem in my life. However, I've been hinding myself all these while. Living in shadow is what I've been doing. I've already lost you in heart. I can't affort to lose you in sight.. I don't want to even lose the only chance to be able to see you and talk to you..

Tell me I'm stupid.. Say I'm idiot.. I'm doing all these to suffer myself.. But what else can I do? I've tried keeping myself busy to keep my mind away from you.. I've tried to ignore you, but I couldn't resist on replying at the end.. I've tried hating you, unfortunately, I've failed.. Tell me what else can I do to not lose the grip of you anymore but at the same time forgetting all that has to do with you?

10 days more I'll be back in M'sia.. Seeing you soon.. Until now I still can't make up my mind on how to face you.. Why you can never see the love and care I have for you? I do not love you cause you your money.. I love you for who you are..