I think my husband may have ADHD, or am I overreacting?

Hi, I have just discovered this website and I feel as though a lightbulb has gone on in my head. My husband and I have been together for 8 years, married for 1 with two children aged 4 and 3 years old. Our 4 year old has always displayed signs of ADHD and he is getting progressively worse - this probed me to start researching into the condition. By doing this I have been overwhelmed by all the signs pointing to the fact that my son has probably inherited this from my husband... Suddenly all the times my husband has stunned me with his seemingly thoughtless, selfish, self centred and impulsive behaviour seems to make sense! It has been breaking my heart that increasingly,particularly in the last 18 months-2 years, I have been secretly wondering if I married the wrong man, and questioning how  someone who was always so positive, laid back and soft as I used to be, ended up with someone who at best is silly and thoughtless and at worst, aggressive, cruel and unpredictable. But am I overreacting? Am I clutching to a 'label' to make myself feel better and possibly excuse my husband's behaviour? A few examples of what he is like:

1.) He is incapable of being sympathetic or empathetic to ANYONE.

2.) He is completely unaware of the poor way he communicates - either he is distant and appears as if he couldn't care less even when I'm in tears imploring with him to listen to me, or he loses his temper with no warning which results in him shouting, swearing, saying cruel things - even in front of our children. He always apologises for this afterwards, but it's as though he can't stop himself the next time he gets angry.

3.) He is a risk taker and an adrenaline junky - he regularly speeds when driving, leaves it to the last minute to brake and gets road rage at the drop of a hat - even with the kids in the car.

4.) He makes decisions regularly which impact on us as a family without discussing it with  me first - and then CANNOT understand why I get upset, insisting that he thought he was making a good decision and just wanted the 'best' for us, although 9 times out of 10 the decision he makes is what suits him the best, not the rest of us.

5.) He has a good playful side but doesn't realise that things he says as a 'joke' can be cruel or offensive to others, he always maintains that he is 'only joking' so therefore it is the other persons fault if they take offense.

6.) He can swing between being moody, bad tempered and impatient to being almost hyper and 'full on'  - playing rough and tumble with the kids and being the life and soul.

They are just a few examples, I would really appreciate it if anyone could give me their opinions - does it sound as if he has ADHD?

Thanks for reading this x