Jim, you've done a phenomenal job! I agree with Sojourner; try & set a more realistic goal, and take some of the pressure off.
It's true that exercise needs to become part of our daily routine. Easier said than done, I know! If it weren't for my dog giving me "the face" every morning, I'd probably plop down at my desk, and not surface for hours. I used to take her to the park; play catch, then sit my butt down on a bench while she plays. Now, I take her out for a good 40-45 minute walk through the hills about 4-5 times a week, which has made a huge difference in my progress. I know I "should" (hate that word) do more, but for now, this seems to be "enough".
You're doing great, Jim.... Keep it realistic, and try not to get down on yourself for not living up to your own expectations. As my father always says, just do the best you can :-)