This is a very real and recurring problem in my own relationship. I was diagnosed as an adult with ADHD and have a son with the same. We're not hyperactive but what used to be called ADD. I suspect both of us are also on the autistic spectrum but that hasn't been explored. My husband recognises a lot of his own behaviour in our son (but not in me). I think that he is defininetly on the autistic sprectrum. I've done a lot of reading since I was diagnosed with ADHD and recognise a lot of issues that my husband and I have had since we got together. Basically he keeps EVERYTHING in and feels better by putting up a protective layer that keeps all his insecurities on the inside and other people outside. Including me. I on the other hand am very impulsive and if I think it, I tend to say it. The worst thing in the world to him is an argument and he takes any criticism as a personal attack. When we do have an argument it escalates very quickly because he shuts down and that makes me boil over. I think we are both full of the same anxiety but our natural response is different - he goes into flight mode and I fight. It has got to the point where I tell him if he walks away from me he can keep walking because I want nothing to do with someone who won't stay and sort things out like grown-ups. This kills him and he has gone into full shut-down sensory overload distraught crying before because he felt trapped and hounded by me.

When we are being rational loving people like we are 99% of the time we make allowances for each other. I understand that whether he has a diagnosis or not he approaches things from a very different place than me, and also that I would be a nightmare to deal with even if he was neurotypical. Together we have a lot of problems. Because he doesn't take criticism well and I blurt it out he often feels under attack. I say to him I would rather know when I am winding him up and he should just tell me but he hates conflict so much he won't. About every 6 months we blow up and nearly get divorced. I think we need couples counselling but the last thing he would want to do is open up to a stranger.

Sorry none of this is actually advice except to let you know that it will be difficult for the two of you and love isn't always enough. But it is something and kindness towards each other is the most important thing. You will only have half of our problems if your gf doesn't also have her own issues. If you are willing to try counselling I think it is a great idea. Good luck!