I am the worst human being ever.
No. You are a HUMAN human being, and you made some terrible choices. It sounds like you are on your way to owning those mistakes.
This is an amazing place to get help...IF you want it.
No matter how deep your hole I can suggest two things: There are those here who's holes were deeper, and who did climb out. And there is hope.
Stick around. Ask questions. Read. And work on YOU. That's the most important thing your spouse needs, whether she or you know it or not.
Welcome. Glad (and sorry) you're here.