Do you think I should separate from my wife because I know that I don't make her happy anymore?
Have you talked to her about how she feels?
She told me that she feels like I don't care for her anymore
While it is hard to end a relationship, you should be honest with your partner. You might be able to fix the relationship or at least end things on a good note.
I told her that I'm unsatisfied because of her.
If you're being honest and you want a divorce then you should ultimately get one, or at least speak with her about trying to make it work out. Either way, something is wrong and you need to try fixing it however you can.