Chris I lack the time to fully reply but two things caught my eye...
when you say things like she deserves better than you, and maybe you should back out of the family, its for HER to decide, not you.
When YOU say it, it seems like a great excuse for you to be in a low expectation mode, so no one will expect much from you like effort, monogamy, honesty, etc...it also smacks of the "woe is ME"...Stop saying it okay? It's not altruistic of you to say or believe.
Interesting that you lost a lot of weight and then cheated. Sounds like ego came into play. Whatever, you'll have to dig deep. It's worth it.
Second, you say it was a one time mistake? It happened over several weeks so how's that one time? You didn't confess until you were caught, so..I'm thinking you should just stop that line of thought. Just do whatever the hell it takes to earn back her trust OVER TIME b/c she can't just give it to you...
Your changes + enough time + divine intervention/luck/power of love= her taking you back.
So make the changes and give it time, and turn the rest of it over to God. Leave the results up to Him.
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016