GoodKarma,
None of us are "heartless," we are all quite strong. More importantly, we are practicing boundaries, self respect, self love, etc. You see, that's the thing, a lot of us (myself included) have been in your position. The painful reality is sometimes we "think we're helping our addict," but in reality, we're actually hurting them more & preventing them from feeling the pain consequences of their actions/behavior. Unfortunately, until you set some firm boundaries, your addict will continue to take advantage of your love and kindness.
When you're exhausted enough and ready for a change, you'll be ready to try something different. Insanity is doing the same thing over & over again and expecting different results. Sending you prayers. Taking the first step is hard.