Asda own brand drinks and food products that proclaim no sugar or no added sugar contain aspartame...I know because I was checking labels last week. Stevia (I think that's spelt right) seems to be ok.
I have a fruit infusion bottle, available from Amazon...
Definitely tell your GP, but don't let him or her hood wink you into believing it is diabetes related, it could be related to the menopause, many of us get a little "clumsy" about that time of our life.