I have always said to myself that I should not or in a stronger way I must not make anyone be my source of happiness, be it my best friend or even my spouse, NO MATTER WHAT!
But strangely enough, when you were in a relationship and every single thing that you did was based on love, sometimes you had no idea how you were going to do it without that person when the relationship is over. That is what I feel sometimes. You cannot act that (s)he does not mean the world to you anymore while (s)he used to mean the world to you before.
Clearly, it shows how unhealthy attachment is, it is very addictive. Isn’t it?