BTW What's your location?
I have a 24K golden crossback and I can relate to what you must be feeling now.
Couple of suggestions from me:
1. In case you feel that the behaviors started after you introduced the tank mates, if possible remove them.
2. Your current 4 ft tank, will be too small in next few months. Try to upgrade to a larger tank asap
3. Water parameters are most important, check the ph, ammonia, nitrate levels and also TDS and chlorine levels regularly. And follow your WC intervals and WC quantity rigorously. Your PH of 7.5 is fine don't worry about changing it.
4. Most importantly, try to introduce varied food for your Aro. They might not like pellets. Try Mealworms, Crickets, Prawns and Shrimps along with pellets. I suggest prawns to start with, they may just work for your case.
My Aro doesn't like pellets like most other Aro, and was not eating properly initially. Once I tried Prawns slices (from regular fish/meat stores) there was no issue there after. These days he eagerly comes towards me anytime I come close to the tank thinking that he is going to get prawns from me lol. He even show his natural jumping instincts when I feed prawns to him, I was so amazed to see it many a times now.
Once he start eating the food that he likes, you can insert the pellets in that food and he will eat pellets too without realizing it. I am doing it like that nowadays.
Cheers