Ever tried to breathe in and not breathe out? It's impossible to do so for long. I guess it's the same with relationships and affection. You cannot keep it in or with you - you have to let it go. That's the only way you will be able to live. Else you'll just die of suffocation.
So the next time you feel like holding onto something - a place, a feeling, a person, a thing - think about what that kind of self-imposed ownership would do to your soul. It will make it stop breathing. Don't do that to yourself. Let it out. And let it go.