Spouse of newly disgnosed ADHD husband

Hello all...first off, I'm a newbie and have been reading a lot of the posts here.  Some give me hope, some scare the living dayligths out of me and some the jury is still out on.  But I am incredibly thankful a place like this exists.

I have been married for over 2 years and been with my husband for 4 years.  We've been through couples counseling for the past 2.5 years and it took a random article that I happened to come across on the internet that made the light bulb go off.  It was an article about adult ADHD and it seemed like someone was telling me about my marriage.

My husband, thankfully, doesn't have problems financially.  Yes, I pay all the bills.  Yes, I handle all our finances.  But he doesn't go off spending without my knowing it and after reading some posts, I am incredibly thankful for this.  His lack of impulse control showed mostly through anger.  He got angry quickly and would say the most awful terrible things that I have ever heard and then an hour later he would tell me he didn't mean it and didn't know why he said it.  And then the next day, it would be like it never occurred.  He also is an impulsive liar, to the point where he'll lie to me while I could see what he was lying about. 

I recently told him that when I talk to him, it's like he's only listening to every 4th word.  Enough to get the gist of what I'm saying but not nearly enough to actually understand what I'm saying.  We've had fights about promises he's forgotten, his career falling apart, his resentment for me treating him like a child, my resentment for having to act like a mother.  We argued about he forgot things we fought about before and how I wished he could love me like he loves things that hold his interest (his iPad, Anime, etc...).  To be honest, our marriage was going to be imploding in a very short time.  I am reaching the end of my rope.

And then I found that article about 3 weeks ago.  And I asked him what he thought.  At first, he denied it 'til he was blue in the face, until he agreed to let me bring it up in counseling.  That led to a psychiatric evaluation and here we are, with an ADHD diagnosis and Concerta at 27mg starting today.

So, I have some questions for all of you.  He's starting meds (cautiously and nervously) today and I want to know what I should be expecting.  Will there be mood swings, irritability, will things get better or worse?  What should I be expecting from this point forward in general?  I'm trying to have hope for all of this, but it's difficult to get over some of the anger and bitterness that I have acquired over the years.  Is there any advice on how I should act and things I should do from the point forward?  Is there any idea how to get passed all the hurt?  I have bought the book The ADHD Effect on Marriage and I started reading it last night.  In all honesty, I'm glad we found out that this was a problem, but I'm terrified at the implications.  It seems like I'll be fighting an uphill battle.  Is this true? 

Thanks for reading and everything.  I really appreciate it.