I've been misled by bipolar

Today DH confided in me that he (in addition to his severe depression) has been having extremely violent thoughts and has a great deal of anger and he wants to go out and fight and hurt someone.

Naturally, I was concerned for my safety, as well as DD's, and I tried to be gentle when I asked him if he needed to go to the hospital, or if maybe we should call someone. Here is what he said:

"I've had episodes like this since I was in 5th or 6th grade, and I've always been able to work through them. So I'm just going to try to stay quite and take my meds until it goes away."

5th or 6th grade???? I think that was before we got married. I'm starting to think that all of this mental health stuff was going on for a lot longer than I thought, and that maybe I just (lucky for me) happened to meet him at a time when he was stable...?

As I wrote that, a thought popped into my head: "Well, if he was stable once, he can get stable again." Which was kind of a strange thought, because the conscious thought that I was having before that, was "Oh no, what have I done?" And things along that line.