I'm sorry to hear you're going through all of this...We've had other members who have had similar experiences with loved ones who have/had Graves Disease.
The thyroid controls several body functions and when the levels are off, it throws the whole body out of kilter. It does cause severe mood swings, irrationality, depression, anxiety, etc.
Do you know what medication your husband is taking and what dosage he's on? Is it an anti-thyroid medication?
He should be getting tested regularly for TSH, Free T4 and Free T3... do you know if he's still doing this? If his thyroid hormone levels are allowed to stay too high for too long, it could damage his heart, eyes, etc. Some effects of Graves Disease may be permanent, some may be reversed with proper treatment.
You mentioned "RI" treatment... Do you mean RAI? That's Radioactive Iodine. Is he getting that or has he already had it? RAI, basically, "kills" the thyroid, so it will produce nothing. This will leave your husband with permanent hypothyroidism, and he will, then, be dependent on replacement thyroid hormones. The hormone dosage will have to adjusted adequately in order for him to feel his best to function normally. Again, he will have to be tested periodically for Free T4, Free T3 and TSH to make sure his thyroid hormone levels are maintained adequately so he feels and functions at his best.