I am a bit confused

Me[20M] married to my wife[21F] are married for 2 years and she is an amazing wife for sure, and I love her with everything. We live in a good apartment in Central London, my wife works as an Industrialist and manages a part of her father's business.

In the beginning of our marriage, I was attracted to her sexually really very much. But after 8 months or so, It began to fade away. I started to foin other women sexually attractive while I don't feel any attraction to my wife that much.

To be true, me and my wife have sex twice a day, she is really good and lovely in bed but I don't find her that type of girl I could get hard to. I sometimes jerk off to some porn to statisfy my urges.

My wife really tries her best to make sex really good between us. I asked my mother in law about this topic and she said that it's completely normal and happens with everyone. But I still don't get it how to build that old level of attraction between me and my wife, like I has for some other teen beautiful girls.

"tl;dr"