When I first started with crystals I was extremely sensitive to the energies. My collection and inventory at home did not bother me, but the first time I went a dealer's warehouse I was completely overwhelmed! I had to keep going outside because my head was spinning, I was dizzy and slightly nauseated too.

I had the same experience the first time I went to Tucson too.

Black tourmaline will help greatly, so will amber. Amber helps you to break the energetic connections. I use amber when I have problems breaking contact with a stone after I have finished a reading for my store.

Your body will adjust to the vibrations of the stones, it will just take time.

Try moving the stones around until you find a comfort zone. You may just have them too concentrated at the moment.

I would keep the rose quartz in you bedroom, and the hematite by your monitor.

You might want to try clearing the stones too if you haven't done so recently. Place them touching the selenite for a few hours, you might have to do it in shifts depending on the size of the selenite.

And if all else fails, tell them they are overwhelming you. Respectively ask them to mute their energies to allow you time to adjust.  

You are just probably not used to them...I have over 100 crystals kept in one room :P

My feeling about this is that you can not have too many crystals in your environment.  After all, who is to say what your "environment" really is?  The crystals are all here existing in harmony here on earth (which is really just like one BIG environment).  So, since space is limitless, we are really surrounded by more crystals than we even know (what's the difference between having 20 stones in our bedroom and having millions on our planet?).  However, for some sensitive people, it may not be wise.  Each person is their own best judge for what is appropriate.  As loing as you feel good in your environment, lots of stones are not a problem.  I would only suggest removing some if you feel overwhelmed, anxious, confused, spaced out, etc.  It is all up to you!  Use your intuition to decide what is best for you.