Fear of Being Alone

Sometimes this thought really occurs in my mind. I am the only child of my parents being total introvert it's difficult for me to talk to poeple from school and college times whenever i made friends(or whom i thought were friends) drifted apart it was me always who took the initiative to call or meet them but when i observed that no such initiatives from their side I too stopped bothering them. Even with my cousins who are pretty older than me i don't have that close bonding they are busy with their lives too. Now with my parents growing old i really sometimes fear that i will not have anyone in this world whom i can talk to despite my best intentions and efforts i am maybe not that likeable that people will want to go out or include me in plans. I am trying to improve and socialize more but just one sided effort doesn't seem to be worth anymore.