This must be very difficult to live with. You are in your 60’s. I’m sure this isn’t the way you want your marriage to go for the rest of your life. It’s tragic that an otherwise good man is eroding his relationship with you this way.
You didn’t say how long this has been going on. If it is recent, a medical exam may be in order. There are a number of medical conditions at your age that can cause heightened anxiety.
If this is a lifelong problem, it is another matter. You can’t change him on your own. He has to want to change.
You may already know what I suggest, so my apologies if I’m suggesting what you’ve done already:
A person like this isn’t likely to respond to accusations or threats or anger. It is more effective to tell him how much you want to be close to him and that the way he is dealing with anxiety is driving a wedge between you. Let him know how sad and disappointed you are that you feel like you have to protect yourself from hurt by pulling away from him.
Ask him to think about this: If you two only have another 10 years together, does he want them to be happy ones or does he want to continue to hurt you and worry you with his yelling?
He will probably tell you not to take it personally and that the yelling helps him — at least temporarily. But the answer to that is that you are the person he is yelling at so of course you do take it personally– and that he may feel better but it is at the price of you feeling worse. Then encourage him to see a therapist to help him learn how to manage his anxiety in a different way.
I hope he will take your advice. I do think that intimacy and closeness is the key to happiness as we age.
I wish you well.