Under tongue irritation and sore area on lingual frenulum - #10191

Hello. I am a 23-year-old male. I am generally healthy. I do not smoke, and I rarely consume alcohol (mostly beer, a few times per month). On November 23, I noticed irritation, redness, and pain under the lingual frenulum (the tissue connecting the tongue to the floor of the mouth). The pain was especially noticeable when moving my tongue. Over the following few days, several whitish, pus-like areas appeared on this region, which I initially thought were aphthous ulcers. Within about one week, the affected area seemed to decrease in size, and the pain with tongue movement also slightly improved. However, as of December 23, I have started to experience general fatigue. I exercise regularly, but I am now noticing increased muscle soreness compared to usual. Additionally, I have observed color changes not only on the frenulum itself but also in the area just above it. There are also whitish areas on the lower lateral sides of the frenulum and small pimple-like spots along the lower edge of my tongue. I am concerned about the possibility of a serious underlying condition. I would appreciate a scientific/medical evaluation of this situation. I have uploaded three photographs showing the progression of the condition.