Hi Wonderingalways and welcome.
As pdm asked, is he always this closed off as in not sharing his emotions much, not talking about how he feels etc.
You mention that you don't want to do anything to upset him and ask how to handle it to keep him healthy. Is that the norm for you two? Do you find yourself tippy-toeing around him so that he doesn't get upset?
You also mention he is stubborn, does this mean in most things? Is he the kind of person that likes to do what he wants and you kind of just have to go along with it?
I ask these things because they are somewhat typical of addictive behaviour.