It is not good, but it is normal.

Since "It is not good" and "It is normal" are both complete sentences, you should put a comma before "but" to separate them.

I have seen a lot of friends tell me that they would never fall in love with someone after they go through a break up.

They start becoming indifferent because they think it can help to protect them away from love hurtingfrom being hurt by love.

Some of them became a playboy or playgirl, and some of them became single beliefs.

I'm not sure what you meant by "single beliefs".

1. Being hurt by love is not the reason you can hurt others in a relationship.

Saying, "Being hurt in a relationship does not mean you can hurt others," would sound more natural.

Being indifferent is usually leads to a pattern of hurting others.

Your partner may feel the/shey loves you so much.

2. Becoming indifferent indicates that you are not strong, because you cannot stand badunpleasant emotions.

3. You can choose those people who make you feel passionate, y. You can leave those people who make you feel indifferent.

Why are you staying in a relationship whichthat makes you feel not unhappy?

I hope you can find the someone who you really want to flirt with and treat that one who is still in your relationship kindly, he/she isyour current partner kindly. They are innocent.