Well i dont know about songs, but certainly for writing you do need a inspiration, a motivation and a figure in mind, else i dont think its possible to write. I am here putting my own opinion though, but it do need a heart to write, heart in right place, and ofcourse a reason to write.
That's what life is all about. You cant control with whom you fall in love. Or with whom you feel comfortable. Its not in your hands but its done automatically. Consider it like, you are walking on the street and you saw a dress and you liked it. You didn't told your mind, you liked it. But your heart and mind told you that you like it. So whom to like and whom not to like, whom to feel comfortable, with whom to share feeling is not in your hands but infect controlled by your inner powers.
But once you do it and you think something has gone wrong.. don't worry. It bought you a wonderful lesson. As said, life takes exam first then teaches the lesson. same way, you learnt a lesson from the exam of the life. Going forward, don't sit back and cry for what has gone wrong. But infect see though things have gone wrong but what I have learnt from it. This attitude will help you in long run and will always help you to look for positive in the lack of negatives.
When person changes, it pinches because we have invested too much hope in that person. But if someone changes, you should not. Like its said, my duty is to love, even if opposite person doesn't love me its ok. I should be grateful to life that it has taught me to love someone and feel the special feeling. and then make it forward and think in tomorrow's way. Don't sit back and see what went wrong. Look ahead and try for better tomorrow. People will hurt us now and then but we should not stop loving. We should not stop caring because that's the way we are. And we should spread this goodness in all direction, at least one day everything will be fine though we may not be here to see it but our efforts will make things better for generations coming. So keep doing good work and keep spreading love, care and affection. Just be your self and take care because you deserve the best of life that can offer.