If you aren't playing competitively (as in specifically going to tournaments) but do play to improve and have fun, just move to another character. The time you put into Puff won't disappear, maybe you'll need a bit of a refresher if you go back to her, maybe you'll find that you prefer someone else, maybe some third option. If you think that maybe this will happen every time you dedicate yourself to one character, then pick up a character (or two) to play on the side every now and then to break the flow. Keep Puff or whoever as your main but having a second character, preferably not one too similar to your main, can help you on days where you just aren't feeling your main or feeling like playing them.