When I got married, my wife was still in college. I had to relocate to a different city two thousand miles away for work. She was supposed to graduate college in two years and then join me. Despite the distance, every thing was smooth for about a year. She was madly in love with me. I have anxiety issues. One day I saw on news that some women who was working alone in coffee shop was harmed by some psychopath. That triggered anxiety in me about my wife as she lived alone too. As she lived so far away from me I started calling her a few times a day to make sure she was alright. She hated that. She kept warning me to stop but I simply didn't listen. Incidences like this led her to eventually lose attraction for me over time. Looking back at my relationship, her love for me was at it's pinnacle when I didn't show excessive care.
It wasn't as though I was just anxious about her. I felt like that about other members in my family too. Harm to my loved ones is the single biggest fear of my life. My brother once went to Nepal with his friends and didn't return on the day he was supposed to be back. I was paralyzed with anxiety and didn't calm down until I called the hotel he was staying in and got in touch with him. However, you can get away with this kind of anxiety with your other family members but usually not with your wife or girl friend.
If you think about it, the love between a husband-wife or girlfriend - boyfriend is the most selfish love of all. You are easily replaceable. A brother doesn't stop loving you just because you have another brother. Parents don't stop loving you just because they have other children. A women will stop loving a man as soon as her attraction for him dwindles or if she finds another man. You are useless for her at that point. Also, you can share your anxiety and fears with your other family members. You can truly be yourself. Not so much with a women.