Marty my friend, we all go through this, some more than others but and all of us go through it in different ways, for some its no motivation to lift some its no motivation to do cardio. I myself at one point had no motivation because my lifting partner was on vacation etc... that was a low point for me and after that I was determined to never miss another workout, also because i felt like crap missing a workout.
Do you take time off from the gym every so often? I usually will try and take a week off every few months just to get away from the sometimes monotony that is the bodybuilding lifestyle.
We aren't normal people, normal people don't wake up at 520am to go lift (as i do) normal people don't eat 7 times a day or go throw heavy weight around for fun, we are a different bread in that aspect but we aren't so different in the aspect that we need to take a break every once in a while.
You have made some outstanding progress in your weight loss that's undeniable! take a look at your before and after pictures, that may even motivate you further, you'll see how far you've come so far and want to push forward.
Here are some quotes that have helped me push past this previously:
"There are three kinds of people in the world - Those who make things happen, those who watch things happen and those who wonder what happened."
"Goals provide the energy source that powers our lives. One of the best ways we can get the most from the energy we have is to focus it. That is what goals can do for us; concentrate our energy." - Denis Waitley
everybody wants to be a bodybuilder but don't nobody want lift no heavy ass weights - "Ronnie Coleman"
“The Ninety-Nines... That’s what I call ‘em. Ninety-nine out of a hundred people can’t fathom what I do. They scratch their heads, can’t believe my dedication to this great sport. Many don’t even think this a sport or that I have a life. Never let others define your ‘life’ for you. This is what I have chosen. This is the road I’ve taken, with all the potholes, bumps, and turns. The Ninety-Nines, they can’t commit 100% to being their best, to step up one day and stand tall among the giants.”
"The plates on each side of the bar...they keep us stable, like bookends...this our life, and another chapter is about to unfold"