Part of having a heart full of feelings is risking the pain caused by something damaging or severing these attachments. It does not mean that having close ties is not worth it. It's a sign that you're doing something right by being a person open and emotionally available to feel closeness, love, and to see positive things in another human being.
Recognize that you are going through a very big emotional experience. Be kind to yourself. Take things slowly. Like being sick physically, when your heart's ties are dramatically impacted, it can send us reeling out of balance for awhile. This takes patience and gentleness to get through. It may feel like a good idea, in some cases, to focus on anger and blame, but remember not to go overboard. Ultimately, you chose the path you are walking, and being excessively negative about the circumstances you are going through can make them worse for you.
Know that it will change in time. Feelings are like the tide. They come in waves. This is an important thing to remember. What you are feeling right now will not be the same way forever. Also, it helps to know that these things ebb and flow when a moment of sadness comes up again suddenly. Instead of despairing over how the heartbreaking feeling is back again, try noticing that it must have been gone for a little while for you to notice its return. Take comfort in the fact that you only have to handle what's right in front of you emotionally to be on your way to healing.
Realize there is a purpose. Heartbreak doesn't happen at random. There is a message in every pain we experience and nothing hurts us uselessly. Knowing this, you are clued in to see what your feelings are really trying to tell you in order to help your life and heart be better and stronger. It could be that you are hurting because you made a choice to trust in a person or situation that was not right for you, and your feelings are letting you know the peril you were put in. When you get burned, it shows you not to put your hand into the fire. Perhaps, a part of what you need to understand from what you are feeling is simply a new found respect for your own amazing capacity for love. With heartbreak comes the understanding that whatever you may have lost, you still have the part of that experience that was created and kept in yourself. Or maybe your feeling of heartbreak is a message trying to tell you that what you were getting from a situation that has ended is something you can gain from a more sure source-- yourself. Looking for what lies beyond the obvious pain can bring tremendous relief and often becomes the guide to mending the heartache you have felt.
Know that heartbreak is intense and feels unbearable and isolating to EVERYBODY. You are not alone at all despite how it feels. Hearts are broken and mend just like yours will. Seeking out support groups or even just other people's stories of how they got through can really help your process be less bumpy.