@cookiecalachuchi,
Ok, first of all, if you're really sad, your first priority shouldn't be wondering if your friends are worried about you... that's kind of egotistical.
second... what is the difference between your friends' interactions with eachother, and with you? Are you talking about the same stuff? same subjects?
Maybe your group of friends don't have the same interests that you have... Or maybe it's your approach... perhaps you should ask the closest of your friends what are you doing wrong...
I've a few guys that certainly approached my in a friendly fashion but were nuissances and irritating. They were unaware of how irritating their conversations were... and maybe I should tell them that they're annoying, but at 30 years of age, they should have a better self-awareness...