Can I be more heartless? I try so hard to make everyone in my life happy and at this point my depression is at an all time high.
That sounds sad. Why are you working so hard trying to make everyone happy, yet you're not happy yourself?
I'm doing it because I know they appreciate me for all my effort.
You are not helping the situation by hurting yourself. Being depressed is a medical condition that needs to be addressed. The people that you think that you are making happy will end up resenting you for the same behavior.
I don't mind if some people hate me. At least I'm making someone fucking happy now.
But their happiness is not real because it is not based on truth. You need to be seeking help now, it is not good for you to be highly depressed.