I Want to Make a Difference In the World

I used to. I wanted to get my fine arts degree and join the peace corps..or work for UNICEF. I wanted to work with children all over the globe helping them cope with trauma through art. I wanted it since I was a kid myself. Now when I say this is what I want to do it doesn't sound genuine. Its just out if habit I tell people now. It sounds unrealistic. My dreams aren't the same. In fact they are oddly simple now.
I can't have kids so I thought I'd be a mother to the world. I thought I was strong enough for that. I've been through so much and I'm still standing. After last year though everything changed. I'm bitter. I lost this very bright thing about me. My kindness has turned to silence and selfishness. I see it. I watch myself. How can I change back. I miss the girl that wanted to make a difference. I was into the feminist movement, human rights, and love in general. Now I dont give a shit to be honest. I dont care. I only care when it comes to myself and even then I dont really care.
I still very much know that there is that person still in me. I know in my heart these are things I want. I just dont know how to truly live for it like in did before.