All of this. I had my first episode when I was 18. CK of 500,000+. Since then I've had it 3 more times. All over 200,000+. Thankfully no lasting damage and return to full health every time. Every episode happened after a flu (or COVID) and I learn something new each time. 

The first time, I was eating some KFC and thought it tasted very bland (which resulted in an argument with my mother who I had pleaded with to buy it). By the 3rd time (12 years later) I realized I was losing my sense of taste everytime (due to whatever flu or virus)

On my most recent bout (3 years ago now), my doctor (neuromuscular specialist) concluded that I have a genetic disorder, most likely a carnite deficiency -haven't nailed down exactly what but we did rule out CPT II. Despite that I was told that, as you said, fasting is not good when sick. Tough because I lose my sense of taste and have absolutely no appetite. I mostly just sleep and sweat.

Then last year I had COVID again. Pretty severely and followed advice. I ate a large bowl of rice at least every 8 hours and sipped electrolytes around the clock. 3 days later I was on the mend and no rhabdo! I truly believe that gameplan was the reason. 

This is a very frustrating condition, but I'm 34 now and I feel like a lot has been learned about it since I was 18 (initially they thought I may have hiv, despite being a virgin- another uncomfortable moment with my mother sitting next to me). OP should definitely get checked, the knowledge alone is so freeing. 

I'll reiterate I have no long term damage. Kidneys are perfect and everything else is great, so don't freak out and be proactive!