Frustrated with current circumstances

Like every other non-ADHD spouse on this website, pretty much everything resonates.  I can relate to just about every post, comment, etc.  Unfortunately.

My fiance (together 3 years, engaged for 2) and I have really hit hard times just before our wedding.  Since we decided to have a wedding a year ago, things have really taken a turn for the worse.  We both realize this has a lot to do with the stress of the wedding planning coupled with the stress of everyday life in an ADHD relationship. We've gone to counseling (until we could no longer afford it), and although it seemed to help a little bit, I wasn't really seeing the changes I wanted to see. With either of us.  Mostly, I felt like the attempt to work on "us" ended after each session.  I never really felt it moving beyond that hour; I guess I never really saw the follow-through. My fiance said he found it extremely helpful, he's willing to try meds, and he's willing to go back when our finances rebound from the wedding. We do have plans to go back to counseling and to get him started on meds in the near future.  

At any rate, my issue is with my ADHD partner's current level of aggression he has toward anything/everything he finds unsuitable.  If I don't understand what he's trying to convey, he begins to aggressively yell at me, repeating the same sentence over and over without answering my question. If I disagree with him, he says I'm criticizing him and that starts an argument.  If the dogs misbehave, he goes overboard with the punishment (to clarify, he's not abusive to them, it's just so much yelling and he scares them, for sure).  If I comment on the fact that his driving is scaring me, I get yelled at and put down.  Basically, he yells about everything under the bloody sun, he'll throw things, break things, slams thing around.  It's over-the-top, ridiculous.  I have to admit over the course of three years, I have begun to react the same way towards him when I get upset.  I am ashamed to say that our fights have gotten physical recently, and I know I play a part in that as well. (Our counselor is aware of the situation.)  I realize that my behavior also needs some work -major work- I'm not letting myself off the hook, here.  I just need some advice.  I don't know how to get him to understand that his reaction to common situations is extreme and needless. Its like I have a toddler throwing a temper tantrum every ten minutes, and has the ability to really do some damage. I need him to see that his reaction to just about everything puts me on the defensive and immediately puts me on edge. (Even scares me sometimes.) I, then, overreact to his reaction and everything just escalates from there. 

Does anyone else have this problem?  How do you handle it?  More importantly, how in the world do you stay calm in the face of such behavior?