Rugby Player on a mission

So... Ive been an amateur rugby union player for more than 20years…always been a fat kid and my weight has fluctuated immensely over the last 10years or so. From 130kg to 102kg. I feel I've never really reached my full potential as a player and this is my next attempt to finally make it happen. I have 5years left to play this game... As it gets harder each year to stay fit enough. Can I do it... There's the question. Staying motivated is hard.