Setting boundaries and maintaining emotional intimacy

I have been married to my husband for 10 years (known him for 18) and we have 3 children 5 and under (we were optimistic), and one of them has autism.  My ADHD husband really, really struggles with our autistic son (who, ironically, is just like him).  Our son takes ALOT of my time & energy.  My husband is often demanding and impulsive, and can drastically undo the work I am doing to maintain a semblance of consistency and sanity in my home.  That is, I have learned certain strategies that work with our son to prevent meltdowns (that are hours long), keep the peace, and create a positive atmosphere and my husband will come in and undo it, and then *I* have to help our autistic son recover and work him back up to being calm again.  I can't tell you how often between the 2 of them, I've considered locking MYSELF up.  I try to deal with them in healthy ways, but their need for control & their anxiety constantly take over my life.

I try to set boundaries, but often my husband doesn't hear the boundaries I try to make.  He gets confused when I try to enforce them.  He argues with me about my boundaries.  All of this continues to disintegrate my emotional connection to him because I just start shutting down now when he argues with me.  When he chooses to argue, I never win, and I never get heard.  He has a hard time interpreting emotions and understanding where I'm coming from or why I say or do something (he could definitely have something more like Aspergers).  He often argues they are MY issues (blame game).  We are currently in marriage counseling, though we have gaps sometimes in when we go, just do to other demands of money and time with our child's therapies.

My question is, how do I set boundaries, keep them, and yet work towards a marriage that is more workable?  I feel like I have to keep putting up walls to stay sane, but I do desire to better love my husband and make this marriage work...

Thanks...