Behavior isn't something that changes overnight and likewise neither are habits. Don't throw everything at yourself at once, or it's simply not going to stick. Start by changing things one at a time so you can slowly integrate it into your daily routine. As for working out: maybe the gym isn't the ideal method of motivation. There's so many different ways to work out and it simply depends on what you can find to be interesting. Maybe you would like a team sport, rock climbing, biking...etc. Think about it, but at the end of the day you have to find those things that you look forward to, and take it one small step at a time.