Yet another citrus question

This Mandarin doesn’t seem to be going as well as it used to. It’s watered, not water logged, started feeding it this year ( a few times, not over feed). I’ve spent a lot of time on stink bug removal but it just does not look well. There’s two citrus trees next to it and they are going well. ChatGPT doesn’t say much so I’m looking at advice or am I a hypochondriac?