I was in a 10 days meditation retreat recently. This experience happened on the 3rd day while I was observing the sensation of the breath on the area below the nose. At certain point I experienced/witnessed what I preceived as awareness without the object, sensation of the breath. It wasn't a still awareness though. It was as if awareness is exciting/stimulating itself. Or to put in other words, it was the process of awareness without an object. Here are the train of thoughts the followed:

1. I had never thought, imagined or conceived of such joy that exists in pure awareness. Awareness that is innocent of worries, expectations, judgement, resistence, boredom, ..etc. Just the joy of awareness
2. Even thoough I  had never imagined such joy, it seemed to me that this was was my original state.
3. The horror of coming back to a world with awareness that is burdened with worry, sadness, plans, demands, ..etc. As if the world is pulling me back to hell.
4. I told myself: no way I'm coming back to my previous awareness.

That was the experience itself. Many things followed, but I don't know if they're relevant. Those 10 days retreats are roller coster rides and it's hard to know what will stick and what will not.

What do you make of my experience?

Second jhana.

Thanks! Anything special I should/shouldn't do because of this experience?

Yes. Do NOT cling to having this experience again. Go back to your practice as you have done it before. If it comes up again, do NOT cling to trying to make it last, or entertain thinking about what it means, or any of that - just notice that it is happening and continue as before. Let it develop as it wishes to, or not.

When your mind gets tired of joy and you relax and sink in space beneath your body, higher jhanas will be accessable. Cause joy will fade you will naturally not cling to it. 

To me it just sounds like a nice experience that occured in meditation. 

I am very skeptical it was the second jhana.  Pleasant, temporary meditative experiences happen sometimes, and they don't ussually fit into neat categories.  Don't expressly cling to it, sure, but also don't push it away.  These expereinces can be a distraction if we cling to them, but are also wholly apreciable for pleasant and potentally insightful aspects. 

Just appreciate it for what it's worth, critically examine your experience to see if it is really changed or affected by it, and then keep at it (meditation)!