I hear what you are saying... I went through that a lot myself... in bed, "nobody's looking", got nothing else to do, I know it's wrong, but boy doesn't it feel good. And then the next morning I felt like I had been up half the night! (Oh, and by the way, all the so-called justifications for acting out all turned out to be complete bunk.)
My question to you is, do you really feel like, as you say, "There is no need for this"? I used to tell myself that after-the-fact a lot, but I realize now it was just a way of assauging my aching conscience for having just fallen. Honestly, doing that, I was just enabling myself... what I really needed to do, and b"H, I've gone a ways in this direction lately, is focusing on what I've been doing and especially thinking (even though it's disgusting), not labelling myself as anything (e.g. "bad", "sinner"), and honestly probing into my kishkes as to why I am doing this - the answer for me was almost always "escape". When I was able to start doing this, I started making some *real* progress.
And almost certainly, both you and I need to do more than what I just said... but I guess I'm considering what I just said as a necessary foundation, and to build from there.
May Hashem grant you hatzlacha rabba in all your worthy efforts.