motivation should be as simple as looking into a full length mirror completely naked.
if you like what you see, then you're on the road to success.
if you don't like what you see, change your diet, hire a personal traininer, hit the gym and endure the pain. it's that simple. there's no secret or quick answer. it's all about setting realistic goals, creating a realistic plan to achieve the goal, and being committed 100% to achieving the goal.
in 6 months, look in the mirror again. if you don't see any changes you need to take corrective action.
I am 38, always had ectomorph physique, but look better today than I was in my 20's. In fact, due to hardcore strength training, I look better than 99% of everybody in the gym. the answer is simple. I work harder than 99% of everybody in the gym. hard work never fails!
confidence builds self-esteem. hard work builds confidence. hardcore strength training builds quality muscle, quality muscle builds confidence.
if eating healthy and hardcore weight training aren't working, you need to refocus.