What happens when the plan fails?

So since April 1st I've been doing a workout plan...yes, it's actually a plan...each day has certain exerices you are supposed to do and certain walking patterns. I have done really well at actually doing them everyday, rather than just when I feel like it. And I can tell!! Yeah for being able to finally wear those jeans I could wear before I started this desk job a year ago!
However, last weekend when I went to McCall I didn't do any weights all weekend (didn't want to take them up there and then watch them sit in my suitcase the entire time!) And since I got back...yes, that's right I still haven't done the weights. I've done the stretches and sit ups and you know the easy stuff without any actual weights...but haven't found the motivation (or really the time) to do the weights yet. Now, it's almost like this weight on my shoulder about feeling guilty for taking a week off and worrying about when I will start doing them again. Will I be sore all over again? Which, I admit isn't so bad, I like that painful feeling...makes me feel like whatever I'm doing is actually affecting my body somehow. But Tuesday, Thursday & Sunday are the WEIGHT workout days, and being as its Thursday I know I need to do something tonight! But I have a dinner downtown Eagle @ 6:30 with my cousins...whom I love, but they can talk for hours :) I know that I will not make it home before 10...so then I have to ask myself will I really have the energy to do anything when I get home? Do I value my sleep more? Will I feel better once I actually do it? haha...I think this whole exercise thing creates more stress in my life then I ever thought it would :) Although I suppose it also helps me relieve stress in other parts of my life! Why is it so difficult to find the time to do something that is so good for me? Yes, I know....probably that same reason its so hard to eat those foods that are good for me :)