I also gave up caffine when I started. Yes.. I went throught major withdrawls, but when it was all done and over with I felt great. It's nice not HAVING to have it. However I do have a couple doses a week. Saturday nights I have my HUGE cup of fully loaded coffee and it keeps me up until 5am (I play a game I'm addicted too and don't want to sleep)

and then I have a small diet coke once a week or when I'm dining out.
It doesn't seem to have effected my weight loss, however I try to be careful that I don't get hooked on it again.
I'd have to say if it makes you happy and helps you to keep better OP.. go for it, just know that it may slow your losses down.