Teeth grinding

AnImaginativeUsername

Hi guys,
My dental hygienist told me in September that the dentin on my lower front teeth is showing quite badly and suggested that I might be grinding my teeth at night. I downloaded an app that can record if you are grinding and have used it every night for about six weeks. There has been no sign at all that I am grinding my teeth, although I'm happy to admit that the app might just be a bit rubbish. However, I also have none of the other teeth grinding symptoms mentioned by my hygienist (headache, jaw ache, earache etc). There is definitely damage going on with those lower front teeth though and thinking about it, it seems to have appeared fairly suddenly. 
Are there other reasons for dentin exposure that I might need to look at? Is there any way to more reliably prove teeth grinding? If it is teeth grinding, what can I try other than a night-time mouthguard (just the thought of which makes me want to gag!). Lastly, I know I can't grow the enamel back but are there any cosmetic treatments or procedures I might need to protect the dentin the future? I know my own dentist is best placed to answer these questions but my dentist is actually 80 miles away (I moved a few years ago but stayed with my dentist because I like them so much) and in Covid times, it's just hard getting there but it's playing on my mind a bit. Thanks for your help.