Any pictures?

Citrus trees are not meant to be grown inside. Put it outside so it can get some natural UV rays and don't water until the soil is dry 1-2" below the surface. You don't mention what type or how often fertilizer is applied. Browning and yellowing could be from over watering, too big a pot, salt build up or over fertilizing. A time line would help too of what you have done.

if you take it outside.. full shade ... for a few weeks.. to harden it off to sun ...

trees need to near dry in between waterings ... if you have been keeping it too wet.. like many houseplants prefer.. that is a possible problem ...

transplanting an already stressed plant.. only heaped stress upon stress ...

only time will see ... ??? .... lol .. time will tell ...

let it near dry in between waterings ...

unless you water so heavily.. that water run out the bottom ... then i highly doubt you need all the fert you are giving it ... you are just not washing it out the bottom ...

lastly.. you are not thinking in tree time .... you say youve increased water.. and decreased water ... but unless you give it months in between... i doubt you could see a difference ....

on some level.. you may be loving it to death ... put it somewhere.. stop moving it.. let it near dry between waterings .. insert finger .. and basically ignore it for a month or 3 ..

ken

Might also have spider mites.