I'm sorry you are going through this. and you are a strong person-because it does take strength to admit you want/need help-emotionally or physically.
It sounds like, from your post, that your husband supports you and how you are feeling. But at the same time puts 'fear' in you, from your view point, if you show to much weakness. That is very scary for you to deal with. But, did he mean the ultimatum has a push you needed to get your act together, b/c maybe he thought this was the only way he knew how to get you to realize you can spiral downward and he can't watch his wife do that to herself. This is a very sensative area for both of you. Is there anyway both of you could see a therapist, if you were up to it? Maybe it would be good for both of you to express your concerns.

(I can relate a little bit to your situation. I stuggle with PMDD and fibromyagia, and I feel at times my husband does not understand at all what I am dealing with inside, and I also feel at times that I can't express it to him because what if he resents me for making our first 2 yrs of marriage an emotional rollar coaster ride that he didn't ask for. )

Have you tried talking to your husband or can your husband come with to your doctor appointment? (My husband comes with me when I go see the psychatrist and Rheumatologist-which I think helps him understand more, he can ask questions and such then. I see my therapist alone. )