Consider becoming active in a sport, even take a college course in tennis/golf/racketball/ballroom dancing. Meet people , go places together, talk, interact, you are not looking for a lot of life time friends, just one or two.
Well you seen what the others are doing so you just do whatever you want... whats stopping you?
Ok and well you should start doing what you want and that'll help you make decisions and if you're having doubts about a decision ask someone... Life is full of risks and well if it goes wrong then its not the end of the world as everybody makes mistakes! :)
What are your dreams? What career do you want to pursue? What are your hobbies? What does your friends do? Do you know why you're indecisive? Are you afraid? Had any bad results from making a decision?
Ok so you do know what you like and want so now you have to find ways to achieve it all and it's possible! You said that you want to be certain on what you want but you've actually answered that!
Ok so you got an idea of what type of career you like to have so you could find out jobs out there that meets it, well can't you just be friend with them all and carry on with meeting them once in a blue moon if thats the way you like it?
Well Just take one path and if you don't like it then go to a different path... life is all about learning and going different directions as it is a journey!
Sounds like you're thinking back a lot too and comparing yourself to other people seeing what they have and what you haven't got...
Also don't forget that the other people could've made a better effort too so it's not all you and you're not to blame for it all!