It sounds like you have a club that has "got in your head." It happens. When this happens, I think what you need is to experience some consistent success to get it back into "auto mode."
I had a full season where I played all my clubs well, but shanked every SW I tried hitting, even little chips. It was ridiculous. So, after watching a late night ad, I bought the F2 shankless wedge. The change in my game was immediate and my shanks were gone. After using the F2 wedges for about a month and getting the shanks out of my head, I went back to my regular wedges and had no more shanks. (But, frankly, I liked the F2s so much that I actually swapped them in and out of my bag for years. I even tried the full iron set, but they were a disaster for me.)
So, like others have said here, I think you need to just back off it a bit and try hitting some softer, solid shots, and then gear it slowly back up. It may take a few range sessions, with solid being the goal, not length. Then, I believe, success will breed success.
BTW, for what it's worth, you may find that soft and solid doesn't translate into a loss of length either. A week or so ago I read something a teaching pro wrote on an online blog. He said: "Many golfers get themselves in trouble with the driver trying to hit it long. The thing is, a hard swing with tense muscles actually moves slower. My mantra is 'slow is smooth, and smooth is fast.'" I went out this last week and said that phrase to myself before every drive and concentrated on swinging as smoothly as I could. I hit all but one fairway with my driver, 3W, and 5W, and hit almost every drive in the centre of the club and LONG. YMMV.
