1. What I mean by don't lose what you may regret is not about money or objects that come and go, those are made to gain and lose to richer your experience of life anyway. What I mean is people, opportunities and chances. People may turn their back easily and may hurt us deeply that's why sometimes we get that feeling of I don't want anyone around me anymore, I'd rather take my pet as the best friend and leave everything behind.
2. This is what we may do when we are emotional, but don't let those feelings control you. You may think about it roughly and say, it's okay to have them as spare tires in my life. Who knows, I may need such persons anytime in this life. This is not bad to go along with when we are still hurt and can't forgive yet, but don't walk much of your road with those feelings as you will be the only one suffering.
3. Think about it rationally and say that they have their reasons, they don't hate us enough to do that but it's their nature, they are much afraid of getting hurt that they hurt first. They don't want to be attached deep to protect themselves from what they may expect from other people. They first of all and finally do it for themselves. They may love themselves more. Then, either you love them enough to forgive those self-loved ones and try to change them slowly or you have a grown-up mind that you think of letting go of the immature or the irrational persons who hurt you unknowingly.
4. This is the most comforting for you. To think rationally and leave a space for understanding and forgiving. It's a case you can solve with the mind. This is for you too, to heal yourself fast by yourself. This way, you won't lose persons, but you will gain more ones. Bad persons or bad-behaving persons keep themselves close to good ones, not because they love them all the time but because they need the kind feelings of security they receive beside them.
5. They may be bad ones in our eyes as we judge what we see, but deep inside them there's always that voice that says one day everything is going to be alright and I won't let me die in this bad shape, I will change, I don't know when but I am sure I will. Being very kind or better saying very reasonable and understanding around them give them the guilty feelings that may grow with time to take them to the road of changing.
6. You may be the reason they do, just be patient around them. Don't let yourself be hurt easily and you can stop them from being bad and it would be the best if you have the patience to change them for them and for your own sake. You may experience this one day and I am sure you will be proud of yourself when you do.