Hypoglycemia makes people snippy, impatient, hostile, or they might start to feel faint. It doesn't make you cry over animal abuse prevention commercials
Dang, I might have that.
Actually...I do have that.
As for Mr INTJ OP - my ISTJ friend is having her second renaissance with her Fi coming out in full force. Your age seems kinda young for Fi to be rearing its head now, but your stressful work situation might be bringing it on as well.
I think it's going to get worse before it gets better. And I agree with folks here who have said "don't try to numb yourself, cut off your emotions, or rationalize them away". Dealing with emergent feeling is like discovering a new sense - it will be bewildering, even scary for a while and you'll have to fumble around to find a way to make sense of it and fit it into your existing arsenal of cognitive functions. Cut yourself some slack and promise that you will not heap retribution upon yourself with hindsight. Perhaps keep a journal to keep track of triggers and find patterns in what you are feeling.
Finally, having said all that - your line of work sounds like it's not for everyone. Even though I have palpably strong Fi and really feel a need to be of service and to right injustices, I decided NOT to go into certain fields because I can't handle it. My issue isn't just necessarily emotional response it's that I end up empathizing so closely with people I need to be advocating for that I get sucked down into the pain instead of being pushed to fight and rectify issues.
Practically speaking what helps is to transmute any pain you feel or recognize in others and turn it into anger against [list evil of the day here] or just general motivation to help them in some way. And feel good knowing that you made someone's day - it will be that much sweeter because you know how low you know they normally feel or how dire their situation is.
In your kind of situation, it's important to keep feeling empowered and capable and even to let seemingly helpless people help you. Once you start getting dragged down by sadness or seeming futility or believing in the effeteness and inherent weakness in others - you're screwed. Time to find a new job at that point.