First of all, you have alot on your plate to have to deal with at one time( Living with critical in-laws, ADHD, new baby, unyeilding wife, and dare I say money problems.) So don't be to hard on yourself. Some ADHD symptoms get worse under stressful situations, and I would say you qualify for severe stress.
If your wife and in-laws are interested in helping instead of just judging then you might get a copy of "driven to distraction." It details some examples of the lives of people with ADHD and offers something to relate to.
Our issues are not visible and obvious, and for too many people this translates to us being lazy or not trying hard enough. Yet you would never ask a person with visible signs, like retardation to "just try harder to not be retarded." I was raised to "hate the sin, not the sinner." I think this also applies with people that have issues like ours. Be mad at the problem, not the person.
Maybe ask them, "Do you people just not like me because you think I somehow choose to act this way? or Do you not understand that I can't just make my mind up to not be disabled?"
There is NO normal. Everyone is screwed up in their own way. They have you looking at your own faults so much that you can't see that they aren't perfect! I will take having ADHD anytime over feeling so insecure and self-righteous about myself that I feel the need to constantly point out someone's faults and not have enough compassion to try to help them. If they cared more about fixing the problem and less about controlling you then maybe they would realize that they are making things worse instead of better.
I'm not a doctor, but I know about being pushed too far, and you need to get some help before you explode. A person can only take so much before he responds to being attacked. I know you have low-esteem, and you don't feel real strong right now, but you have a child now, and for his sake you can't keep taking abuse till you explode. Just remember that you may be ok with taking abuse because they let you live under their roof, but at the same time, through example, your teaching your son that taking abuse is ok.
If you can't afford a doctor, then go to the public library and check out some books.
Check at work and see if they offer any kind of assistance.
If its your thing, then go to a church and ask for some kind of counseling.
I can relate to living with someone who invalidates you as a person everyday. Im out of the situation now, and will never tolorate it again. As far as you feeling your naive and don't know things. I'm 36 and my wife had an affair for a year before I could see through my niavity and see it. Sometimes the situation can lend its self to someone seeming knowledgeable or not.
I will tell you that the strong people in life are the ones who take punishment and forgive, and not the people that dish out the pain. You are strong, whether you can see it right now or not. Try drawing strength from what you do well, instead of dwelling on what you can't do. You won't get better until you decide to stop beating yourself up like the other people.
Good Luck
I feel for you many_minds. As Parduse said, stress can cause the brain to function even less effectively than unstressed. You may have been able to compensate for a while, but as the stress and responsibilities increased, so did the symptoms.
You might try educating your family on the issues with ADHD and tell them that you could use help in getting to a doc for treatment. Unfortunately, many people think ADHD is just an excuse (this is where the education comes in).
You say that you have ADD. Did you have a diagnosis when you were younger? If so, talking to a GP can sometimes get you a trial on meds (try something generic for the lower cost). Some docs are more likely to try antidepressants on adults first if there is no written history of ADHD. Even these can be helpful and are used as a second line of medication.