I, as your GP prescribed, suggest that U get the VA treatment up there ASAP! and avoid reading GOOGLE.
It may be sore/painful especially if there is physical resistance, as the vaginal tissues may well be dry, stingy [which can happen when putting anything inside, including VA treatment initially], once the walls are plumped up it will be easier and more comfortable. What's the worst that could happen?
If U have KY Jelly then put a little inside the vaginal opening whilst laying on the bed B4 inserting the pessary. If it's very sore don't put the pessary in too deeply until symptoms ease which should be within 2-3 nights. Some ladies avoid VA treatment as they have been told that we shouldn't 'touch down there', however, sometimes it is essential to get treatment in order to avoid repeated urethra irritation.