Thanks for providing more information.
Well as you describe it suggests fissured tongue which is a benign condition characterized by deep grooves in the dorsum of the tongue. Although it is painless and causing no physical discomfort.
Fissured tongue often accompany geographic tongue.
Some causes of geographic tongue include eating any of a range of exacerbating/spicy foods, drinking alcohol, or during times of stress, illness, or hormonal surges.
One other possibility is that you have thrush, which is a white coating beginning to develop on your tongue. This is a fungal overgrowth that is caused by a depressed immune system or a severely dry mouth.
You should keep yourself hydrated with plenty of fluids.
Also your doctor may advise Nystatin
oral suspension in case of oral thrush.
I hope this helps.
If you have any further query then feel free to ask.