In your case, it is not a crack in your tongue, but a crack in your tongue coating, which is called "cracked tongue" in Chinese medicine. There are three main diseases: 1, caused by overheating, 2, blood deficiency, 3, spleen deficiency. Given that your tongue is a little fat, you can judge that your cracked tongue is caused by spleen deficiency, and "wet" is the most likely to hurt the spleen. You can't transport water after spleen deficiency, which causes the water to stay somewhere and cause "swelling", so your tongue will be a little fat.
Frequent masturbation will have an impact on the kidney, which is the innate foundation and the spleen is the acquired foundation. The sufficiency of kidney essence depends on the nurture, so too frequent masturbation will also affect the spleen.
In this case, you should not only limit the frequency of masturbation, but also pay attention to the spleen conditioning at ordinary times. It is suggested to go to the local Chinese medicine hospital to prescribe some spleen-invigorating drugs for invigorating qi and spleen.