EXTREMELY weird Eating habits

So a while back a got this beautiful nicaraguan boa. He has been eating fine, hes about 4 1/2 feet... eating 1lg rat a week. THen all of sudden he stopped eating, became very aggressive,(He was never, he was braught to a carrer day event where 300 kids played with him, he was such a sweet heart) and also always has a foot of his body going up the side of the tank, and will stay like that for hours. I tried feeding him every week for 2 months, with no success. And one time he actually went for the rat, and i am not exaggerating but he missed 17 strikes. then a couple weeks later (Which would be today) i tried a small rat, and he just stared at it for hours, and the rat even went to sleep, so i left him in there together over night, ( My snake could hold its own against a newborn rat) and when i woke up it looked like he had killed it eaten, and regurgitated it. i Have no idea whats up with him, i think i am just going to take him to the vet, but i was hoping mabey some of you guys could help a little bit.

him missing strikes that many times sounds like nuro issues.... vet the only one who can tell you whats up, we can all say it sounds like "this" but it will do no good until its checked out.