Look... this is a confidence problem. Nobody is perfect; stop telling yourself you haven't grown up. You already faced more at 13 than most people with the death of your father and almost automatic distress of your mother that resulted. This does not inhibit maturity, it brings it on faster than most people.
So you don't take out the garbage or lock all the doors at the right time? Meaningless, we are all imperfect. Sure, work on the little things, they are important. But you are missing the real problem.
Your wife, likely also in her early twenties, has not matured enough to understand the importance of your marriage (a sacred institution) particularly with a child. Be patient with that, but don't let some sophmoric desire for romance (which always wanes after about two of years of marriage, but is replaced by a long term bond necessary for raising a family) put your child through a divorce.
That will be terrible for your son and will ultimately be bad for both of you. Remember, if there is a maturity gap here, it is likely your wife who needs to catch up only because she's not dealt with the same level of challenges that you have. Don't give in to the temptation to point a finger back at your wife. It's too easy for someone to just displace blame by claiming their partner is dysfunctional. That's what your wife is doing.
Get your confidence up. Stop beating yourself up. Marriage trouble always hits at around two years, when the romance seems to fade. It's normal and it's not your fault. Work through this and don't let yourself fall into the trap of self loathing. Finally, remember, women are not attracted to a man with no self-confidence.
I'm in agreement with your post 166. This guy's post cannot be taken at face value. Something big is missing: the wife's faults. That said it all to me. If he really were a miserable spouse, he would be angry and blaming her for this, not admitting guilt and seeking advice. This is not the post of a bad husband and father.