But at the same time, every new adult decision that comes up makes me question if I am adult enough to deal with it. I take care of it and deal with it, but in the back of my mind I am constantly thinking I am not mature enough to deal with this stuff. But maybe that's the difference; I keep those fears and doubts tucked away and just solve the problem.
I can't agree more with you here. While I have a somewhat privileged background, I've faced a lot of rather difficult situations for my age... and each one makes me question whether I'm really cut out for this.
Becoming a man, in my opinion, isn't about coming of age, paying your bills, your actions with woman, or such. It is about being responsible. If you make a mistake, you admit to it, you try to resolve it. And you make decisions knowing you will be accountable for them.
For me, this realization and transformation took some time, but started when I watched my father pass on. He was, in a way, an "answer-key" to life, full of knowledge and wisdom. Of course, I got some money via insurance, which I squandered away over a year, rather carefree and generally intoxicated. And now, over a year later, I am working, going to school, trying to juggle helping and talking with my remaining family, and understanding life goes on, despite whatever inconveniences you may have.
In a nutshell, you're a man when you realize life keeps going, regardless of how badly you screw up, and it is your job to pick yourself back up and keep going along with it, no excuses.