I think we are dealing with two separate issues. One is your desire to have relationships with people and the second is the fact the you are feeling used and taken advantage of by your current friends.
It is very natural and normal to want relationships with other people. In existential philosophy this would be considered the need for human communication. In other words, people want significant relationships or relationships of meaning. Often this is achieved through family but it is also easily achieved through friendship. You might find this through volunteer work that would have you directly involved with others. Friends are where you find them. That might include at work, in the neighborhood, at school, or at the bus stop. I would encourage you to seek out meaningful relationships.
Looking at the second issue, it seems that the friends you currently have do not reciprocate your level of concern. They don’t treat you as well as you treat them. If you give them more than they are giving you, then they are taking advantage of you.
If I could put this in a simple way, I would give you this analogy. If you each gave the other money and you gave more than your friend, over time you would have no money and your friend would have all the money you once had. It is essential in a relationship that over time you have given each other things of equal value. Perhaps you plan a birthday party for a friend and they do not plan one for you. This would seem unequal. However, perhaps your friend who has never given you a birthday party takes you to the store every weekend for groceries. Though your friend has never given you a birthday party, she has given you something of equal value. Likewise, perhaps last year your friend did more for you than you did for her but this year you are doing more for her than she is for you. This is another example of equality in a friendship.
It is very possible that your current friends are not giving you as much as you are giving them. In this case, you should feel taken advantage of. The cure for this, of course, is to find new friends. Finding new friends does not mean that you must disown your current friends. Instead it means that you should find friends who will reciprocate your level of caring and it will be those friends that you have deeper relationships with. You should invest more in those friends who will reciprocate your level of caring.
I hope that this has helped; if not please write back so that I could attempt to be of further assistance.