First of all love yourself love your every scars every weakness, then you don't have to pretend to be happy, you'll feel happier soon from your own, being apathetic makes us lonely . You need seek out your deepest desires and work on it

First of all, thank you for the encouragement. I do appreciate it. I know it is very crazy. But, I always try to forget about good memories happened in my life because of the reason that if I frequently miss those beautiful memories often, I would be addicted to good feeling, and eventually it would become my weakness. So, I never gave myself a chance to remember those beautiful memories. For me, the more the previous and beautiful one memory is, the faster it should be forgotten. It is usually like that. I know, it is not a good idea, but can't help, I have no idea of fixing it. I am afraid to be happy because I know storms are always waiting to enter our lives at unknown time with unknown reason. So, I must be tough enough to be ready to face those storms anytime and I know remembering the past beautiful memories would only makes me soft and weak. That's why I always live in a dull life which is full of regrets. I am just training myself to get used to the pain. If I can become numb to the pain, then I can be really emotionless. When I become truly emotionless, nothing can affect me, or hurt me at all. So, that would be great. Some people think I am good, capable and strong, but in reality they don't know that I am just an useless coward who is even afraid to feel happy. Also, I have zero self confidence and full of doubts about me and my true ability. I don't know how to overcome that. I don't even know, why I am living for.

You will have to start appreciating and accepting yourself, from their you will be able to manifest a positive sense of self.

You have a weak loving personality which can hit hard in emotional moments. I've also gone through this situation, and gradually I realized having faith on yourself is the most important part. Start loving non living things which can be your hobbies or superior features. Which makes you unique from others. Always know that everything happens for a reason, and all the lessons you received from your past are worth living. Discover yourself, control yourself, and always have a belief that you are worthy for everything you want.