“I am naturally a very nuturing person, and am the first person to think of myself second. Why is it asdfadsf ”

You're being too permissive. This unconditional love things sound romantic but it's completely foolish. That's what pets do, loving anybody for no reason. You should be giving to people who give back to you. Otherwise you'll waste that energy on people who figure out (or habitually) they can just use you. Of course that creates bad feelings.