DP has two personalities. I'm not just talking mood swings, he is literally a completely different person from time to time. The nice side is almost perfect. He's funny, caring, attentive, always puts DS and me first - all the stuff you would want and expect from a DP. Yes there are flaws in that personality (let's call this one Jekyll), he is human, but all around we are very happy and I love him to bits. DS thinks the sun shines out of his (Jekyll's) arse and all of his friends think he has the coolest dad. (To be fair, when he's this person, so do I.)
However from time to time he turns into someone completely different (let's call him Hyde). When he's like this, he is horrible to be around. I hate him like this. He's miserable, aggressive, selfish, and can change the mood in a room the moment he walks into it. Sometimes when he's like this I just lock myself in the bathroom for ages to avoid being around him. He makes me feel like I'm treading on eggshells and it seems like he makes DS feel the same. It's not often that this Hyde personality comes out but when it does it just makes everything we've got normally seem so pointless.
There is a strong history of mental health issues in his family and I wonder if this could be the problem, or does he just turn into a horrible person when he's tired? It's so hard to speak with him about because when he's being Jekyll he just laughs it off as if I'm exaggerating and when he's Hyde he responds with things like "we can't all be perfect like you" or worse "we can all come from perfect families like you" (in fact, neither of us do and Jekyll knows that perfectly well.)
We've been together ten years and it's neither gotten better or worse over that time. I'm just so exhausted with it. I really don't want to LTB (if he actually a bastard if it is a mental health problem?) because I am so happy with our life together normally, I just don't know how much more of Hyde I can take living with. Any advice would be appreciated.