I was the exact same when I decided to play through the game with the alternate costumes. (It was terribly hard for me to go through the first part of the game without picking up anything. *Sigh* I had a compelling urge to nab that first aid spray in the alley and all that ammo but I restrained myself!) All I can tell you to do is just pace yourself. When you feel like playing, play and when you don't...well don't! Don't force yourself if you're not feeling it because then you'll just hate the whole experience and, eventually, the game. Start the game and if you get bored, turn it off and go onto something else; sooner or later you'll be sitting around going: "mmm...I really want to play RE2 right now" and that's when you'll pop it in and go for it. It's like your mind has to get adjusted to the idea first.