Staying motivated Watch
Motivation for me comes from accomplishment (progress). So for me every time I set a strength PB I get some extra motivation.
Also I take a long term perspective- I plan on being 5 years older, so when I actually am 5 years older, why not be incredibly fit and strong (keep training for the 5 years in the interim) rather than be horribly average?
I think 'clean' is a terrible concept. I eat a reasonably healthy diet, I cook most of my meals from scratch, put a bit of thought into getting a varied amount of veg and all that. But I still love cake and chocolate and eat it a few times a week, it's the moderation not the total lack that matters. I love food, I'm a live to eat type, so I've made the effort to learn to cook decent meals so eating reasonably healthy isn't painful.
What you need to do is find some means to make it difficult not to do what you should be doing. For example, only buying clean food, and having a set time for working out in your weekly routine to avoid putting it off til later.