There are a lot of flavored carbonated drinks out there that have no sugar or sweeteners.
Like any change, it does take a little getting used to, but you can still enjoy the flavor and the fizz without the sugar.
We have found that making small lifestyle changes slowly works better than going cold turkey. The first thing we did when we got married was get used to eating brown rice instead of white rice. Now we love and and almost never do the white rice.
We also switched to honey for sweetening some things and cut sugar in half and using real butter instead of margarine. Almost any recipe can work well with sugar cut way back.
I have started with orange juice : )