I’m sorry your husband’s stress so often becomes your stress as well. It can’t be good for your marriage. What you didn’t mention is whether this is new behavior or something that has been going on for years.
If it is new, he needs to see his doctor. Changes in personality at your age are sometimes an indication of an emerging physical illness. Sometimes the answer to such a change is as simple as a vitamin supplement. Sometimes the issue is more serious. But early detection is important either way.
If this is a long established behavior: There is little you can do if he isn’t interested in changing. You can’t make him address it. You can’t ease his stress. You can only tell him what you told us — that his behavior makes it hard for you to be close to him and that his level of anxiety worries you. You can ask him to get some help so your senior years together aren’t marred by anxiety he can’t control.
If he won’t deal with it, what you can do is go for some counseling yourself. I suggest this, not because I think there is something wrong with you, but because a counselor can hear your whole story and therefore may have some ideas for how to invite your husband to come as well. You also deserve some support.
I wish you well.