I don't see how spending some time on yourself, pampering, going out, doing things just for you is ever going to be a bad thing regardless of if he comes back or not.
Try to imagine it was you who left him, imagine all the things that used to drive you up the wall and you can't ever think you will want him back then imagine he rang you daily begging for you back (but you were still so set on not going back because the things that bugged you were still bugging you) imagine he is sat in tears everyday drinking and smoking heavily, comfort eating, living in a total mess, he smells cus he's spending all day in bed and isn't showering, snot and beer stains down his top etc etc imagine worst case senario......yet everyday he is begging you to go back. You would be thinking "wtf he is out of his mind, go back to him yuck!"
OR
You leave him he begs you back for a bit but then after a while he picks himself up dusts himself down starts looking and smelling good!! He's out having a great time and you start remembering the way he was when you met him, you want to be going out with him enjoying his new found life, his job is going well, the house is tidy there's even loo roll (why is it men who live alone have no loo roll?!) and he's quit the drinking, smoking, gambling, comfort eating, he's in the gym 3 times a week, he's learnt to cook gormet food etc etc because with this time he had spent being distraught he has now put it to good use.
Do you see what I mean?
DISCLAIMER im not saying you are doing any of the above as I don't know you its a very very general view.