Can i find my love for my wife again?

My wife and i have been married for 18 months now and we have a 6 month old baby. She has a 10 year old daughter from her previous marriage. We come from different countries, fell in love and got married 6 months after we met each other.. Throughout our relationship we've always had fights about practically everything but after every fight we seemed to get closer and learn more about each other. During her pregancy things got pretty hectic ans she treated me really bad...verbal abuse, even throwing things at me. She accused me of so many things and she really cut me deep. After the brith of our boy things seemed magical for a few weeks and then all the fighting started again. Divorce was a word we often used and the fights even became physical at times. She seemed to push and push untill she got some response from me. A few weeks ago we hit rock bottom. Something inside me changed. There was a complete lack of desire to even respond to her and she blew up. It got really ugly but the end of the night we were both in tears on the floor. We talked for hours and she realised so many things that she have done and hurts from her previous relationships that she hasnt resolved yet and projected onto our marriage. Since then she has been "perfect". Her temper is gone, She treats me with respect and i think for the first time ever she truly appreciates me. The problem is that she is almost a whole new person...the person i was longing for all along... but now i find it difficult to be attracted to her. At times she feels like a complete stranger. In my chest there is like a feeling of numbness. I`ve been researching this so much and everywhere they tell you that you have to work at it. Be like before. Do things you did in the beginning. Yet even when we make love i feel like a barrier... sometimes i avoid her kisses. She is being so wonderful and i feel so guilty for not being able to embrace this gorgeous and wonderful woman i have now...yet a part of me feel that too many scars have left too much hurt. I have been thinking of quitting the marriage and being with someone else...but how do i do that to my son. Yet i also know that if i cannot "fix" my heart then there is only sadness at the end of this road for all of us. Perhaps this is just a transitional phase for me when "in love" changes to "real love"... but if this is how it is then i think love is over rated. I`m a good guy and i want to do the right thing, but i hate that i feel i`m betraying myself at times. Will it just take "work" and if that then what work is required. Is love truly a choice like they say happiness is ... is it more cognition that emotion. I need your help please. I do not wish to cause hurt to anyone and i so wish she could have made these changes a few months ago. I`m convinced then i would have been able to feel different. but now i dont know... Can what has been broken be rebuild... or are there too many cracks in this mirror. Your help is truly appreciated. Thank you.