OP, you sure have it in for yourself, don't you.
Success is relative to what makes you content. You're 21, married, two kids...and just wondering if all the decisions you've made thus far have been the right ones to get you where you want to be or go? What isn't normal about that? I commend you for having sense!
Listen. I remember being 21 and all I wanted was an M3. Fast forward to now, and the M3 has fallen from oblivion in my perimeters, even when it could have been a reality. Things change as you get older, and willingly, so do your circumstances, and all for the better.
Come up with a game plan on where you want to be at 25 and at 30 for starters. In a few years' time see where you've been, and where you are. Progress ain't fast or cheap. But it's progressive.
You can be hard on yourself, I won't tell you not to be. It's healthy and (in my opinion) mandatory. What else can you measure your success by if you aren't hard on yourself?
You just want to see your horizons. I cannot fault you on that. Just keep persevering. And find a way to mark your accomplishments. Year 1, Year 5 and Year 10, etc.
At 21, you have absolutely nothing to go off of, (5 years ago when you were 16?) and thus, the reason why you find yourself in such doubt and frustration.
Lastly, it's understandable why your wife cannot work now-you don't ever want to work just to pay all of daycare.
But I'll tell you right now, if she isn't anxious or being proactive about creating a Year 5 plan (that's how long it takes for a child to become school age), then you should be.
Good luck and God speed.
I (still) want my inner circular headlights gleaming a glowing red. That way, scurry when you see my Demon advancing.