Two critical things you must do if you really wish it to work.

1. Neutral ground HONEST communication.
2. Get him to a doctor ASAP.

Prostate cancer is a real concern here (my Grandfather had ED, never went to the doctor and died from prostate cancer).

There are several other medical reasons (MANopause, Obesity, diabetes, enlarged prostate...) , emotional reasons (likes men now, lost the zing, self-conscious of himself...) and personal reasons (doesn't find you attractive...) that can cause ED or have signs of ED.

If he were mad at you, I would think there would be other signs.

Best of luck to both you.