I have a hard time showing compassion for others?

Hmmm try this:

1. Ask who are you? Are you X? No your are not your name that is a label. You are not the outside world because you are experiencing it. Who is the experiencer? Is it your thoughts and emotions? No. You can have no thoughts and still be you. If you feel nothing and think nothing you still exist. Who are you then? You are consciousness, awareness, and an intuitive sense of existence. If you take away your awareness you do not exist, unlike your thoughts and emotions. There are emotionless and thoughtless beings out there but there are no aware-less beings out there. Unless you count rocks :P

2. Knowing this you can watch your thoughts and emotions. Take comfort in the fact that you are not the sadness you feel or the negative thoughts you think. You can be still and stop thinking. You can choose to say "This rain sucks" "This rain rocks it saved my crops" or say nothing. You give meaning to everything and you have the power to give and change the meaning of things.

3. Crying is good. Expressing is good. It takes courage. Just take comfort in the fact that everything else around you including what happens inside of you (thoughts and emotions) are not you. You are watching all of those things.

4. Force yourself to express yourself. Tell John that what he said made you feel bad. Express all your emotions and forgive yourself and others for the pain they caused you. Holding onto pain will only cause you more pain and will have no effect on those who caused you the pain regardless of whether you let go/forgave or hold onto the pain.

My advice is not clear cut or organized since I am tired and I am in Vegas, but I hope you can find something useful in there.

Depression is often described as frozen emotions. You can watch things but not feel them personally. You find yourself crying but often without a particular trigger. If this is recent it could have to do with seasonal depression but either way you need to talk to your doctor. Your emotions are sending you false signals. I've been through it and there is no more shame in getting meds. to correct this balance than for a diabetic to take insulin. It's all just getting the chemical balance right.

It's particularly hard at this time of year when you are supposed to be feeling all sorts of things. Please be good to yourself and get this treated. Best of luck.

You are not cold hearted silly, cold hearted people do not cry.

Peering in a peer.