Day 279 - Letting Go

I was talking to a friend of mine about 2 relational situations that we are both aware of.  One of them is a situation in which the folks are together, and the girl is all in, but the guy isn't (for a few reasons).  The problem is that the guy refuses to let the girl go, and she is too deeply invested to free herself.  In the other situation, the girl recognized that her partner was having a difficult time with things, and so she let go.  We were discussing the dynamics of the 2 situations, and it got me thinking about letting go.
As with most things, the media has done us a disservice by showing us break-ups where there is a major fight or angry scene, because that's where the drama is.  They don't typically show the break-ups where things don't quite fit for one reason or another.  The love is still there.  The connection is still there.  Neither person wants to let go.  But for some reason or circumstance within the situation, things just won't work in a way that won't cause undo pain that can't be outweighed by the positive in the situation...
So what do you do when there is no "major" reason to break up, but you know in your heart that it'd be best (esp if not for you but for the other person) to let them go?  I've learned that you have to push past your own needs/desires and let them go.  You have to love them enough to do what is best for them even if it is the last thing you want.  Otherwise, you don't really love the person.  You are being selfish when you see that a person is hurting and you put your desire to be in relationship with them (and the needs they meet for you) ahead of their needs and feelings. 
In the first situation described above, neither party has the love necessary to make this situation healthy - love for the other person (to let them go) and love for self (to leave an unhealthy situation when it cause as much pain as it does despite the positives).  In the second one, they were willing to bite the bullet and do the hard thing.  They knew it was better to do the healthy thing and let go even though their feelings didn't dictate such an action.  Was it esay?  No.  There was pain and wrestling and agonizing on both sides, but in the end, it was better to part of the sake of emotional health than to hold on just to be together.
So the questions on the table: can you love someone enough to put their heart first?  Can you love yourself enough to leave when it's unhealthy?