It can be done. Our backgrounds are remarkably similar. (13 year IT career, worked full-time or more during undergrad.)
I'm in my 2nd semester of a full-time program. I can still coach/assist my son's various teams. I still have business interests outside of school. I'm divorced, and my ex has a schedule that means I've got my kid more days than not. My grades? I thought I worked pretty hard for them, but they're pretty unremarkable. (3.088 on about a 2.8 curve.) I do think that the time I spend with my son is part of the reason why I'm not closer to the dean's list, but that's a tradeoff I'll take any day. We went to Disney for Thanksgiving, for instance, instead of me using that precious time to prepare for finals, which is what I should have been doing from a Law School perspective.
Personally, I don't think it's that hard to graduate from law school. It's very hard to graduate from the top of your class, though. So, it sort of depends. If you really want to set the curve, you're going to have to put in more time and effort than I did.
Personally, I feel like I've got 17 years with my son, then he's off to college and off to make his way in the world. I want to make the most of every single year. Even if I could get top 10% (which is debatable and maybe even doubtful), would I give up 3 of my remaining 7 years to do it? Then plug away 60-70 hours a week as a new associate in a big-money job for 5 years afterwards?
Been there. Done that. Made a good amount of money working in a corporate career. Made just as much, with less effort, and a lot more enjoyment, having my own company. I'm not eager to return to a desk for 60 hours a week.
Money isn't everything and I think there are plenty of ways to make a lot of money in the law without selling your soul and giving up your family life. In fact, if family is a priority, the law allows you to have a career with flexible hours where you're well compensated for the hours you work. It can be the worst thing that ever happened to your family life, or the best. I think which one it is is entirely up to you.
I say go for it. You seem like a smart, focused, capable person. Maybe give it 110% for the first semester. If you place top 10%, you can assess what to do from there. If you are, say, in the middle of the pack, frankly, you can probably stay there with a lot less effort.
I don't think you're selfish or crazy, but if you are, so am I. So, maybe I can't recognize it.