This is an amazing question. I have wrestled with thoughts like this as well.
(does your IT job really pay 750k annually or is that a typo?)
This question seems a subset of "How much time/money/effort should we spend helping others, and how much on making ourselves happy?" There is obviously no right answer, and it's complicated by the fact that helping others can bring you joy as well... to a point.
In my own life, I do make a priority of helping others (in a community-wide sense, not just helping out friends/family) but I do it in the ways that align with my own interests and how I want to spend my time, not necessarily the most impactful.
I don't personally think it's a good idea to become a martyr... to essentially negate yourself in order to give to others. Ultimately you are trying to bring happiness to others (I assume), in the form of reaching their human potential through education. But if you rob yourself of happiness in the process, you are causing harm while doing good.
Obviously some level of sacrifice for others is worthwhile and noble... but where you draw the line is up to you. To me, working a job I seriously dislike and am burned out from in order to give money to the needy is more than I am willing to do. There are so many other ways to give back and to do good in the world. You mentioned one -- volunteering at the school -- and there are countless others.
Your story resonated with me because I was teaching after-school programs at a school for at-risk youth in Washington DC and I met their IT contractor, who wasn't volunteering but who gave them very low rates and worked extra unpaid hours because he believed in the mission, and that connection changed my life. Working together with that IT guy led to me being able to greatly expand the program and help a lot of young people.
I know you will find what works best for you. If it were me, I would quit that job tomorrow and explore ways to help those kids that don't involve being burned out at a job you don't like.