Diabetic ED

So my husband is a type 1 diabetic and has never had good control of it. Lately we've been having a problem and he can't get it up and/or keep it up. Most of the problem is in his head and he gets frustrated and won't stop thinking about it making it even harder for us. Anyone else experience this? Any advice? We have tried everything to try to occupy his mind but nothing seems to work. Help?