If it were only masturbation (including the issur, spiritual/mental/interpersonal damage that it causes and its onesh as I understand them all in my heart) that I considered my big problem, I doubt I'd have ever stopped. I went on with it for years and cried my eyes out, ripped my ego to shreds with guilt and shame, fasted, mikvah'd and tikkun'd my brains out - all the while hiding and carefully guarding my dirty secret. I never actually gave it up and did what I really needed to stay quit until the problem became much more to me than "just" losing my olam haba, "more" than going to gehinnom, and "more" than being tied in a knot with fire burning at both its ends. Apparently, I had to come to see that I couldn't continue one more step in my double life, or I'd lose my G-d, my morality, and my entire world as I knew it. I liken myself in this prat to Iyov, who R"l lost all his kids, estate and stuff, but never cracked - that is, until he got tzora'as. The meforshim explain that when it finally touched his very body - what he identified with at the deepest personal level, he couldn't take it any more.
Am I saying I had no emunah? That I really didn't take the onashim warned of in chazal seriously, etc..? Perhaps yes. I do not really know - nor do I care. Perhaps if I really believed it all b'chush, it'd worked more in my heart to stop me. But the pain of the lusting lifestyle is what stopped me - not the aveiro.
And I am not alone: When the great Tanna RYB"Z (I think) was dying, he advised his students to learn how to have an awareness of Hashem's presence that is as powerful as the simple presence of a man in the room with them. They said, "That's it?". He answered:, "ummmm. Hellooo! Hal'vai they should be the same for (you) people!" (cynical dramatization added by me!) Now, perhaps I totally misinterpret this story and surely there is some m'forash that takes it out of the apparent p'shat. But it seems valid and plain to me. I actually expected myself to be greater in simple emunah than these great people! What unbridled ga'avah. In fact, it seems that my very pride itself was always my worst enemy: It always told me that I could really stop (a lie), and that I was therefore a loser for ever failing!
Back to my point: In general, in my emotions - my heart - my reality - the seriousness of aveiros, per se', simply does not even come close to the shame of actually being caught or paying in an immediate way for a mistake. And takanos and k'nasos are artificial, BTW. Natural consequences teach.
I am not interested in whether this is a shanda - only in the functional truth. We need honesty.
I am sober today as a result of this derech, it seems, and my life (and family members' lives) has been improving in ways I'd never have even wished for, in every respect.
I have far to go, but every year is definitely far better than one before, which is kind of bizarre given what kind of goofball I am.