Hi there, My Dad is the same, diagnosed last year at 59. He has Fronto-temporal Dementia and his memory is the least affected, its his behaviour, reactions, feelings that all changed. He never swore which he now does, he can be very agitated and aggressive (he's currently under a section but thats a story for another time) Medication has helped although its not at the moment, keep pushing forward for the scan. I really had to push to get a date within 2-3 months, otherwise they wanted him to wait 6 months plus and I refused, i even said I would take him day after day and wait for a cancellation, that seemed to do the trick. The Scan showed severe atrophy in the frontal and bi lobes (FTD) and with some in the hippocampus region which is typically Alzheimers I believe.
All I can say is keep pushing until you have the information you need and a diagnosis, we were very lucky from what I read here, my Dads original GP appointment was 16th April 2018 and full diagnosis following a Scan was 15th July 2018, however as I said above, I didn't take no for an answer as we were just in limbo.
Good Luck, Adele