His whole, “It’s in your head” stance is borderline gaslighting and, yes, it would appear that he lacks empathy. And unfortunately, I have NEVER seen a guy develop empathy over time. I’m guessing there are red flags about him that led you to hide this condition from him for over 4 years to begin with.
I have been where you are/were, minus the substance abuse. I used to have panic attacks during difficult arguments, and (when I was alone) I’d hit my head on the wall, pull my hair, go outside at night in winter in thin pj’s, etc. In hindsight, it was an attempt to externalize (and thus have some control over) the emotional pain I was feeling.
The good news is that you won’t always necessarily be this way. The bad news is that you likely won’t make much progress while in a relationship with this man. He will continue to gaslight you, guilt you, and in general be non-supportive. If you hope to ever get better, you will need to either be single, or to be with a partner who makes you feel safe, who actively supports you – EMOTIONALLY, not just physically.
My SO knows I can have panic attacks and that I have PTSD. He does thoughtful things all the time that let me know he’s always thinking about this side of me, not ignoring it or trying to forget it like it’s somesort of ugliness in me that he’d prefer to avoid. And when we went to Hibachi dinner with his dad and brother, and the hibachi chef pretended to squirt something at my face that wound up just being cloth, and I burst into tears from the shock and ran to the bathroom to breath through a mini panic attack, SO didn’t treat me like a crazy person. He just explained to his dad and brother that I have PTSD, then came and checked on me, then treated me completely normally the rest of the night, while being extra affectionate.
^^You need and deserve that kind of support. You deserve to not be made to feel like your anxiety is your fault, or like it’s a terrible thing about you that is hard for others to accept.
Because of SO’s support, I feel safe, which has drastically lessened my anxiety. I haven’t had a panic attack in well over a year, and we almost never argue. The key is that I feel safe and loved – for ALL of me, not just the “happy, bubbly” part of me. He never judges me or treats me like I’m inadequate or a hindrance on him.
If I were you, I would have a come to Jesus talk with him, give him some time to adjust, but let him know that he either pulls a 180, reads up on your condition, give you 100% emotional support, or you will prioritize your own health and happiness and go it alone.