Zina with wife's sister ( sister in law)

I was reading about zina with wife's sister ( sister in law) and I read that according to Hanafi madhab Zina with sister of wife ( sister in law) break Nikah between husband and wife even if someone touch his sister in law with desire. I hand shaked with my sister in law long time ago but I'm not sure was it with desire or it was just a normal hand shaked. There is no relationship between me and my sister in law but sometimes Shiatan was putting bad thoughts in my mind about her. Now I'm very confused and scared that is my Nikah with my wife still valid. If its not valid what should we do? Should we do another fresh Nikah.