TRT doesn't cause water retention; elevated estradiol does. There are quick and easy two ways to lower it: lower TRT dose or take an ai. Do you have a recent blood test?
Reducing body fat will help to keep e levels in better shape.
Unrelated to hormones, reducing sodium and/or going on a low carb diet will help your body hold less water.
I'm guessing here, but I doubt water retention would cause sleep apnea, but it might make it worse.
Are you over weight? This may be the leading cause of sleep apnea.
Did you get your screen name in prison?