You sound very insecure about your relationship. Don't let it be the only thing in your life - you need a life too. Don't chase him up, don't ask for reassurance - otherwise he has a controlling streak in this relationship. Just trust him, and if he goes to the gym, you find your own interests too. There is quite an age difference between you - in those nine years, people start to get different priorities (as you'll find when you get to 27). He says he loves you - stop freaking.