In need of advice from women with mental illnesses

My husband and I are 3 months away from being together 6 years and married one year. I am bipolar and as anyone with bipolar knows it kinda come hand and had with depression and anxiety as well. I found out I was bipolar when I was 14 so my husband has known about it all along but unfortunately it not something he has ever understood. I have had a pretty good hold on it for a while now so it hasn’t really been an issue, he has seen some on the mild side episodes but nothing full blown. But lately the depression accompanying my bipolar has gotten way worse to where I am feeling the need to inform someone, I have no friends, and no family that will give a damn it’s just been my husband and I looking out for each other. I haven’t been in this stage of depression since I was 16 so he has never seen this or experienced it with me and I seem to not be able to tell him or maybe I’m just afraid to...after a health scare with my husband last year he developed anxiety and luckily because anxiety and I were no strangers to each other I haven been able to help him deal with it and help him through attacks. But he is having a really hard time at the moment going through a lot with himself and his family that I don’t want to add to that or in any way add more stress and make his anxiety worse, but I am starting to fear my own thoughts and recognizing the place I’m getting to mentally and I know I need him and his support and help but I don’t know how to ask for it when he himself is going through so much and has never quite understood the severity of the depression partnered with my bipolar. I have tried to stay so strong for him but I’m really struggling now. How do I tell/talk to him about this?