The fight AFTER the fight

Hi. I'm new to this forum but I'm glad I found it. 

My boyfriend and I have been together for nearly 2 years and he is the absolute love of my life and the man I will marry and have a family with. We've overcome many obstacles with his ADHD and are still learning to work things out. However, there are a few things that have consistently been a struggle. I'm hoping you all can enlighten me with some other strategies.

We disagree, argue and fight, as any couple does. We've talked about how sometimes afterwards, we may or may not need our space and should be respectful of that. Even though we talk about it, it's always a struggle. Several times, after I am emotionally worked up, he will throw in "I'm sorry" with the expectation of "I said sorry so everything is fine now." He'll then come to me right after and expect hugs and kisses and if I can't give them to him the way he likes it, then he gets angry with me saying that I hold a grudge/need to get over it/"I said sorry". This all takes place about 30 seconds after 1hr of arguing and a 2 second apology. If I tell him that I need some time, he gets offended. After I've let my emotions come back down to normal range and I try to talk about something else & move on, he's unresponsive or gives me the cold shoulder or an attitude. When I ask him why he's doing that, he says "well you're mad at me"...

How do I react to that? When I tell him I'm not mad, I just needed some space, he'll throw it back and proclaim "well I'm giving it to you" in a resentful way. I've taken my space, I've come back to him, but it just doesn't seem like a very apologetic way to react especially considering his emphasis on the fact he said "sorry". He doesn't ACT like he's sorry, despite him saying the words, and the tension starts rising again...

How can I avoid the fight after a fight?