Let me make a number of suggestions for you that might help you to understand the situation and might suggest ways to proceed. I am also a mechanical engineer and there is a possibility that you might find that you are not so 'left brained' as you think and that is all in your training, not in your nature. Tom Campbell long ago on the board introduced us to the 16 personality types studied in some way by many but specifically in the most advanced form by Dr. David Keirsey and written about in his book Please Understand Me II
. You can find this on the Internet under these terms. His book is available as an eBook for ~$10 on the Internet and the test for your personality type is in the book or you can pay for the full results on his site and there is somewhere that you can find by search to take the same test with no charge, or at least there recently was. This concept goes back to Aristotle who wrote about the 4 main types (each with 4 sub types) called Artisans, Guardians (of society), Idealists (the true right brainers) and Rationals (the true left brainers). And by the way, the concept of left brain/right brain has been shown to not really be correct.
The reason I bring this up is that it can possibly be a way to gloss over the present kerfuffle with your family by attributing it to your being these different personality types. The reasoning is as follows. Tom introduced himself as being a Rational Architect (of systems, not houses) which under this system is known as an INTP (Introverted, iNtuitive, Thinking, Perception based thinking). I test as an Idealist Counselor (and frequently mystics) known as INFJ (Introverted, iNtuitive, Feeling, Judgemental). Tom Campbell created this elaborate theory of Consciousness while here I am counseling you, both true to form. You made this discovery which you looked up on the Internet and voila, a possible basis for resolution and self discovery. I suspect that you might find that your husband is a true to form Rational from what you say about him. You sound like you are an Idealist of some form or other and also your son. Not to say that none of you could be an Artisan or a Guardian. But the idea is as you would find in the book suggested that these 16 personality types each have their own characteristic ways of thinking and thus agreeing or disagreeing, the degree that they get locked into a particular pattern of though, or not, and their ways of getting along together and understanding each other, or not.
Do you see where this might be a useful tool and approach to reconciliation and rapprochement? No certainty as I do not know your actual types and can only guess. And you must still manage the negotiations to produce the desired result. But that's what engineers do, put things together to do useful things. And wives have been managing their husbands (and vice versa) to reconcile differences since there has been the custom of marriage. Where there is a will, there is a way. So that's suggestion one.
For number two, more information for you to look at which might show you more of and different complementary aspects of Tom Campbell's theory. Have you heard of Tom's Wiki and the write up of his model of Reality there: viewtopic.php?f=265&t=10393#p95781
You will find that the core of Tom's model goes back to ancient India as Indra's Net. I have sent you by this path so you will see that there is much more there and there are also links to other resources if you go up a level to the full Board forum containing these threads.
You might also take a look at my own site which I put up about the same time that Tom put up his and we thus 'found' each other. http://www.active-mysticism.com/
This will show you that there are many other sources and ways into this same basic understanding of Reality as I have been studying the same thing as Tom has from a different direction all my life, just as Tom has.
That's enough to dump on you for now. Consider the first suggestion as I think it is a real approach that might
work by catching your husband's attention on a great 'left brain' explanation (and diversion) for the whole situation. Best of luck.
Oh, and not to forget your question. Tom considers ego and fear to be different sides of the same coin with ego a development to oppose fears. From your husband's point of view, this situation probably represented a primal fear arising that his wife of umpteen years together has suddenly turned into someone he does not really know or understand and attacked his whole world view, turning everything upside down. Suddenly he is defending every aspect of his life and the primary line of defense is ego.