Go a head and ban yourself if you want. But if you ask me, I'd love you in the phone group I am a part of. In fact, your mess is small potatoes compared to most guys on it.
Terminal uniqueness?
Yes, I and others here have done far worse than what you describe here. More accurately: when I act out my lust, I do much, much worse than what you describe. But so what? Would you like me to detail it for you? No problem - but not on the forum. We can talk on the phone.
With respect to the old mental trick of "I am such a disgusting stinker that I might as well do worse and get it over with," I have a surprise for you. You will discover it yourself when, c"v, you "finish off the aveirah and move on," as you put it. The secret is that you will not 'move on', of course. We are not books. Everything we do has a reaction that is real and stays with us, no matter what. 'Finishing the aveirah' is not a finish of anything, but actually a start! It will 100% guarantee a new need within the person, instead of 'satisfying' him. This is just the way it is.
Ironically, this is the other side of very same trick that people like me fall for when we just hold our their breath! I mean when we are not really giving anything up, but just postponing it. Gevalt. The more days we 'tzaddikim' are clean for, the worse our situation grows - the stronger our belief that we have 'sacrificed', and deserve a break...so eventually we must explode. Waiting to exhale.
What do you want? That you have a problem of some kind is clear. What are you doing and how do you want things to be? That is what needs to be made clear. Until then, assessing and blasting yourself is an exercise in futility.
If you are ill and depressed, then please quit blaming your penis, your yetzer hora, or whatever, and get treatment. And if that is what you need, then you are still not nearly alone!