I have a male 1.5 year old Hog Island Boa. When we first brought him home, he was as gentle as can be! After about a week he became very aggressive. I posted a thread about him a couple weeks ago, (at first I thought it might be connected to feeding) and received some great advice/recommendations. We have tried them all but to no avail. So far we have:

Covered his tank and left him alone for the better part of a week.

Dropped the temps from 92 basking/85 ambient to 85 basking/75 ambient.

The guy I got him from had him in a 20 Gallon Tank and I had put him into a 40 long, so it was suggested to me that he may be feeling insecure in that large of a tank. So I transferred him to a smaller rubbermaid tub. It has enough room for his water dish and two hides. I moved him to a different room. He has been in it about 5 days and is worse than ever!
After we left him alone in the bigger cage, I began picking him up with a hook and gloves. He was aggressive in his cage but once he had been out for about 5 minutes, he calmed down and was docile. I would then take off the gloves and hold him like usual.
Now he is staying agitated and readily hisses and strikes even when he has been out of the cage for 10 minutes or more. He hisses and is ready to strike as soon as he hears the lid move on his cage. He stays mad in his cage for long periods of time.

I'm not sure what else to try. I feel bad for him, because obviously he is not happy.
Also, I have noticed that the pupils in his eyes are different sizes. They both enlarge and contract but are never the same size. Is this normal?
Any advice or input would be greatly appreciated!
Thank you!