Why am I so intent on having friends?

i just graduated from high school and I've blown through a number of social ties over the last four years with few people left to show for it. I've hopped from group to group. I find that most of my friendships start off very strong but eventually, person after person will just grow weary of me. Just last week I thought I had found a new friend but now he is lofty with texting me back and shows little interest in hanging out with me outside of a group. I don't know if I even particularly enjoy being with people: I find conversation as sometimes introspective (on my part) but the other person I am speaking with usually has less to say. I believe I need friends because I need people to care about me, as is average, but unlike some people I know I just have no interest in partying or being with a large quantity of different people all of the time. I like a few friends quality over quantity. Anyways, the point is I over-analyze my friendships quite a bit and can't necessarily trust anybody, but why do I still need people in my life?