In his absence...

I've had a tendency towards staying home in the past. Now I really feel I need protection and stay home a lot. Not physical protection, but emotional. I never have had a lot of friends. I made a new friend during the course of my time with him,and after knowing her for six months,she just stopped being a friend. I still don't know why. She wouldn't tell me. I saw her on the street a few times, we both ignored each other. Can anyone relate? I don't know why...