Looking for that perfect job

I have no idea why looking for that perfect job is so hard. I know exactly what I want but wish I knew where to go to find it. I really want to be able to use my schooling (History degree) and help people living in Africa but the job I want does not seem to exist. I can not afford to donate to these causes as I don't have a lot of spare cash and I do donate what i can. I really want to work at a job that impacts peoples lives in a positive way. Also, as I have two young children I would love to be able to work as home as much as possible so I could also assist them in their lives. I really wish I could just design my perfect job and have someone out there hire me. I'd love to help the women in certain areas of Africa get on their feet and protect their children from being forced into armies and having to flee their villages at the night. I'd love to help these people get proper homes and irrigation systems and allow them to eat on a regular basis. What we could do if everyone in the world could get vaccinations and have health care. I wish I could help all these people or feel like I was making a difference instead of just writing about how I want to make a difference. Is there someone out there who has a clue on where I can go to find a job like this?