Breaking off a haraam relationship

Q: I have one problem and I need to know that what should I do. I am 28 years old and married 6 years ago but 3 years back I met a guy on chat. We became close friends, we even started loving each other but many times I feel that I am doing wrong. I am cheating my husband. I decided to break relation with that guy but don't know, I feel like I hurt that guy as he was in love. Now without letting him know any reason, I am not in contact with this guy because I don't want to do any sinful deed anymore. I want to know that did I do the right thing? But one feeling is still in my mind that maybe I hurt that guy and maybe he will not forgive me. Please guide me what should I do?

Tahajjud Salaah

Q: Allah Ta'ala affords and blesses me with Tahajjud. Some times a few minutes before Fajr, I am sometimes so rushed to perform this ibaadah that I tend to forget the proper way, mindset and recommended acts whilst performing this Salaah. Please give me advice on what my connection, mindset should be like at this mubarak time.

Thinking of death

Q: Everything was going smoothly, but since a month I am in a lot of troubles. These troubles are mainly psychological. I am unable to concentrate on my studies. Rather it is like I want to study but I am unable to due to lack of determination, will power, etc. I am lost and I don't know what should I do. I waste a lot of time these days in idiotic activities. I just want to stop this but I am unable to. Please help me in this matter. If there is a dua to overcome such distress please do give me.