should i be more heartless?

The line where you stop is when it's hurting you to help. As long as you're not crossing that, you can be as kind as you want.

As Hopefullylesspretentious alludes to, it depends on the situation, person, time, etc. Some people, maybe even most people, will like that about you. Some will take advantage of it to get some self-imposed pity or whatever. I, for example, would probably never talk to you (in person. On here doesn't count). Just depends.