Frustration leads to thinking way too much sometimes, slow down and be really patient and give yourself a chance, you have already said you have tried everything, trust me you have not tried everything yet, if the water is stained and you are having trouble, think about this, if you are in a dark room that you have been in 100 times, how long does it take you to find the door?
Usually we will wait for our eyes to adjust and look for a light or something to guide us to some part of that room we want to go, think about a fish in dark or stained water, the first thing those stuborn fish will do is listen for something familure using their sensory along their sides, once they pick up the noise or vibration they move to investigate the sound until they can use their eyes and lock onto a target.
SLOW DOWN and don't get frustrated, find something that will peak their interest, something with a SMALL clicking sound will get their attention, the big ones are silent, slow moving, stealthy machines, they have figured out what others have not, silence is golden.
If you throw top water use long pauses and let the bait sit on top, move it ever so slightly with one, maybe two quick twitches, and let it sit again, and keep repeating and playing with the cadience until you get the right one.
Anything under the surface would make just enough noise to attract attention with small movements so the fish won't have to keep looking for it, give them a chance to find the bait and hone in, a small clicker on a worm rig or a swim jig with a very small clicker swimming by the suspended ones would be my suggestion and things of that nature in colors that will match the forage of that lake.