I need career advice!

Hello everyone,
I need help finding an answer to the predicament that I’m in.
Over the course of a few years, my worldview has recently changed into one where I must devote my life--using a career--to assist humans that suffer the most on earth; this needs to happen in order to bring fulfillment and meaning to my life. However, due to OCD (I believe it impairs decision making) and lack of information, I can’t seem to pinpoint the group of humans that objectively suffer the most. In the recent past, I typed up a little argument thing explaining why I am stuck in life, and I think it would be beneficial for you all to see. I will paste it at the end of this post.
The need to help people does not come from wanting to be looked up to, pride, or a "holier than thou" attitude: it comes from the Golden Rule and empathy: I'd like for people to help me if I were in some of these miserable existence's shoes. I can feel their agony, and I know that I would never want to suffer that much. I would want someone to assist me; I would want the suffering to end.
I can think of many people that need help, but I’m not sure how to find a nice little, objective list of what causes the most miserable, agonizing existences. The way my mind works--probably due to the OCD--is that I always need to have the best, highest, elitist, most significant everything. And in the case of a career to help others, I believe helping the people that need the most assistance is respectable and possible. I just need help learning and getting there! Sure, I can go back to college now and maybe major in a health field, but because I haven’t became aware of other possible majors, I will probably regret my choice and wonder if another major would have prepared me for a more respectable career--one that would allow me to help people who suffer in a worse way than said major did. This is a recurring thought process, and I am getting absolutely nowhere. The staying in my parent’s house is already old, and I want to get my life of meaning started!
Possible afflictors could be bad mental problems (like depression or schizo), lack of food or water, lack of medical care, filthy living conditions, physically handicapped/mentally challenged, diseased, forced work (slavery), war torture, sex trafficking, or bullying. I also need to factor in the fact that since some folks are used to certain types of hardships, their suffering won't be as bad as outsiders perceive; this further complicated matters.
Up until now in this post I have focused on the demand/need side of choosing a career, but an equally important side is that of my innate skills and interests. I know for a fact that a social career would NOT be a fit for me: I am a big introvert. I'd like to work "behind the scenes," so to speak. I know that this will limit my potential for meaningful change, but I am not a "people person". Also, my worst subject in school was math: I do not need a math-related career. However, after taking close to 20 career tests, I know that I excel in attention to detail, being precise, and following orderly directions. That is the attribute that scored the highest in most of the career tests. So, I’m fully aware that “me” will significantly diminish the range of career choices that I will be happy with. But here is the argument that I mentioned in the first paragraph:

1. It's conceivable there is a group of humans on earth that have endured the most suffering of the worst type; these humans will have underwent prolonged agony to an extent that death is a highly attractive option.
2. In order to bring meaning to my life, I must have a career where I can assist the members of said group to a place where death is no longer desired.
3. I am unable to pinpoint what type of suffering said group is dealing with.
4. I am unable to choose a major to help me prepare for the career.
5. I am unable to work where I need to be.
Respectfully,
Shane