Black arowana eating/health issues

I have a 16+ inch black arowana I have had from 8 inches. He used to be in with 4 peacock bass and 2 leo rays, but I have sold the 4 peacock bass to pay for a third leo ray. He had no issue eating, would eat several peices of smelt shrimp or worms everyday with no issues. Sometimes he would zoom in first when he was really hungry, but most times he would let the bass go at it first. Ever since I removed the bass from the tank, he has not eaten right since. It took him 3-4 days to eat the first time, and now eats 1 peice of food a day since, and thats at best, sometimes doesnt eat at all. I am wondering if it is because of lack of competition? Either way, I notice him hanging out pretty low lately, sometimes in a corner up high not moving, and must be a bit more skittish because there are a few rips in his fin that are somewhat new (I hate that after a certain age the rips dont heal, in 4 places its not healed, otherwise MINT condition, bugs me, same with his one crooked feeler that grew back after I caught him to relocate once ) which must be from him hitting the lid. Another symptom is one slightly-very cloudy eye which I am 95% sure is caused when he goes down to eat food off the bottom, as he smacks it sideways on the gravel. I once even noticed him go down and grab a mouthful of gravel at night with no food being there, and then spit it out.

Tank is a 7x2x4wide 400 gallon, has a jebao wp40 powerhead in it and 2 mag1800 pumps leading to a solid 90 gallon wet dry sump, also running through a 65 watt UV sterilizer. Water conditions are average, change in bioload/PH fluctuations from changes in stock has long evened out, the new ray is separated for an unrelated reason so its not her bugging him.

Any thoughts as to what is causing this? Not noticing any bulges or anything, have never seen him poop since I got him but my worst fear is that he swallowed a rock. Let me know if you want pics or further info.

Thanks.

The eye is not cloudy from that, I am 95% sure it is from when he goes down to the bottom to grab food, it is just slight outside damage.

Yea my old silver went a month and a half, not overly stressed about the eating itself more its overall condition. Do you have gravel in your tank? That is why I think the eye is cloudy, cuz its cloudy on te surface, does heal after a while, and then happens again. This has been going on for a good while now, with the eye healing completely sometimes. It is predominantly on the side i see him choose when he eats as well. Only mentioned it because it has been consistent lately. I would like to sit and observe him because maybe he's behaving weird at night, but the problem is as soon as I am around he acts differently, he is very aware when someone is looking at him (to the point you cant even look at him face to face, he turns his head one direction or other to make sure he sees you).

Thank you for your suggestion.

So just an update, it has been about a week since he ate. Has some darker scales from jumping and hitting the lid im sure, few new tears in his top fin which I hate. Eye cloudniess ahs gotten better cuz hes not eating. Really wonder what's bugging him, it sucks he used to be so vibrant and active and now hes getting darker and you can tell somethings up. All other fish are perfectly fine.