I dont have great answers for you but you need to tell him if you still care about him, thats major in keeping the relationship as alright as possible even if its rocky right now. All I see in this post is that you need him and that is different than caring if he is ok because you care about him.

Please don't take that the wrong way, this is your only post I have read lately so I could be getting the wrong impression as I dont know what your relationship is really like or what exactly you have said to him.

Im really sorry you are dealing with those thoughts at the same time as you are dealing with him having trouble. When my husband went through a really bad time I was luckily stable.

Maybe try spending some time in bed if possible just talking to him about other things and see if you can move to your concerns for him when it feels right. My husband and I have extremely open communication now so this might not work for you but when he started making comments that worried me I showed him a "suicide scale" I had found and he told me what number he was actually at. It let me know how bad it really was without him having to try to explain.