I totally agree.I think the best you can do for Smudge in the long run,is to leave him on TOTW,but transition slowly. Done properly,his system will adjust to the change,and he'll be happier for it,as well as you.
I know you are on a tight budget,and I certainly can sympathize (Brian has not had a full check now going on a month,because of short time) But for the price of a bag of something,you will have your base food,to add small increments of TOTW,and work from there. After maybe a day on some chicken & rice,to settle his system.
As far as treats,I would not be giving him to many,(actually none,would be the prefered) it can only make more problems,as his digeative tract & bowel are already irritated.
It is a good food,its available in stores,(Tractor Supply) and probaby many more that you may not be aware of. You can find out where,just by going to the site,and looking where by state etc.
I do not think that the formula of TOTW,was the reason his eye looks better,but I'm sure it is because of the vibrant pets,has certainly helped,plus the flareup is healing. Because you have taken measures to help him get thru this,cause you are such a great mom.