I sometimes have no emotions at all
What do you think causes this?
It feels like something is missing like a computer without software
If you feel like you dont have any emotions then you may need to work on letting your emotions out. You may have gotten to a point where you have bottled them up for so long that they are starting to affect your natural personality. Talk to someone, it would be very helpful im sure.
I just don't feel any inside me.
Then you need to get professional help. This isn't something you can  just get over on your own.