You unfortunately did not mention which "cream" the GP prescribed. That is of some significance.
How was a "viral" infection diagnosed? To my mind, Candida - a yeast similar to a fungus - is the common culprit.
The advice of the Phimocure marketers is deliberately very cautious, erring on the side of conservatism - taking things very slowly and carefully - in order to avoid any possibility of people having bad experiences. In fact, you can almost always use the devices for most or even all of the day as long as they are not excessively tight and you should on this account, trial them for just an hour or so to begin with and work up to the longer wearing periods as you gain confidence.
Please beware that the initial impressive results are usually temporary and that further progress will occur, but may be much slower. Please count on not just a few, but many weeks to achieve full resolution, including a month or so after you actually achieve whatever you define as your "objective".