GEL is absolutely right. You must act in spite of your fear of your W.
I'm going to take the liberty of putting an Undefended Love spin on this: arjnex, go off by yourself somewhere and think about reaching out to your wife either sexually or in affection and imagine (or remember) the worst, most hurtful time... imagine feeling as rejected, worthless, dejected, hopeless, etc., as you have EVER felt. And then just stay with that feeling. Cry if you want/need to, but avoid explaining, re-describing it to yourself, telling yourself it will be better, telling yourself it will never be better-- just try to abandon all self-talk. Banish all logic, reasoning, and adult thinking for the duration of this experiement. Be like a baby in a crib crying and not knowing if anyone will ever come. If you can do this and stick with it, this feeling will eventually (after a few minutes) go away.
The level of fear you experience when contemplating touching your W tells me that this is a very old fear. It is disproportionate to the current situation, as GEL pointed out. This fear of your W's displeasure is left over from a time when you were a child and depended on the good favor of your caregivers for your very survival. Now you are an adult, and your survival no longer depends on the favor of anyone unless they are standing in front of you with a gun. Not to say that life wouldn't be better if you and your W had more warmth before you, but you don't need to be afraid of her at the level that you are.
Go to that place where you are afraid and sit with the fear for a while, not naming it, not distracting yourself, not explaining or justifying (believe me, this can be a challenge, and this process is done more easily with a facilitator-- but you CAN do it alone).
