How do you make exercise a non-negotiable?

So, I am really trying to get on the healthy lifestyle bandwagon. I have been overweight my entire adult life, partially I believe due to uncontrolled/untreated depression. Well, now I am taking a daily "happy pill" and honestly it has changed my life! I have more energy, I am more excited about life in general and even my relationships are better. I truly believe that for the first time in my life I have the tools I need to take control of my life and get healthy.

My major stumbling block is exercise. I have 3 horses and I do all their care myself (hubby helps), so I get anywhere from 1 hour to 3-4 hours of "semi-exercise" most days. I say semi because it is just motion, not really cardio, but at least I am off the couch. Cleaning stalls, dumping water buckets, etc. But, it is tiring, especially at my current weight. I really want to get into a structured exercise routine, but I just hate getting up early to walk/do exercise DVDs, and once I am done at the barn in the afternoons, I am DONE if you know what I mean! I work from 7:40-3:10, and I usually get home from the barn by 6pm, so time is not really an excuse. I have a variety of DVDs, everything from yoga to ball exercises to cardio, and I have a nice park to walk my dogs in across from my subdivision, so I really have no excuse!

I guess I just need motivation and a kick in the rear from others who do not enjoy structured exercise. How do you force yourself to get up early and not just hit the snooze button like I did Monday (set it for 5:30 and snoozed until 6:35 ). Part of me thinks I would do better if I tell myself I only need to do it 3 x per week, the other part of me thinks the consistency of getting up at the same time every day would be better. Someone kick my butt and get me on track! Thanks!