I need to add something. I compared Clark with the Danish father who killed his daughter. But a huge, enormous, humongous difference between Clark and that Danish father is that the Danish father almost certainly didn't love his daughter, whereas Clark loves Lois so much that... well, you said it yourself, Rac. Clark's very essence is that he loves Lois Lane.
What I think your Clark can't bear is the thought of seeing whatever love Lois still has for him, whatever illusions she still may have about his bravery and strength and nobility and whatnot, die when he tells her of his (to him) unforgivable shortcomings. I think he fears that he will see a certain light go out in her eyes when he confesses to her what he is and what he has done, and after that light in her eyes has gone out, she will never love him again. And that very lack of that light in his eyes will be an incrimination so harsh that he will not be able to go on living afterwards. Clark is the man who loves Lois, but in this fic, he feels like the man who can't go on living after Lois has lost absolutely all her faith in him, which is what she will do after he confesses to her what he has become.
Yes, but Clark still fights for his marriage and his love for Lois. That is why, in desperation, he sought out Dr. Friskin even though it wasn't time for his regular session with her.
Somewhere, somehow, Clark still wants to find a way to make his marriage to Lois work. Because nothing means more to him than her acceptance of him as her husband.
Ann