I think there is a difference between being suicidal and not wanting to live. I think not wanting to live is because you are filled with hopelessness (possible for no reason or something unrelated to your relstionship). It must have been hard for him to admit that. I told my wife that once and it did not go over well. I believe her words were "if you want to kill yourself leave me first"

I think he was reaching out to you because he feels depressed.

I think suicidal is different. I think at the point were you are suicidal you just cannot cope with issues and you get consumed with dying. Everything becomes skewed and all you can see is the bad and want out.

I wish you and your husband luck in finding a way to resolve how he feels and find some healing. Talking is a good step. Try to be supportive and don't blame yourself or feel like it is something about how he feels about you. How he feels is most likely has way more to do with him than his environment.