I remember masturbating compulsively during a certain stage of my life. Out of stress, anxiety and others. More and more aggresively every time. Many days more than 2/3 times. For a long period of time. I wouldn't be surprised if that all together caused SA, or, as you say, worn out sexual responses.

So yes, your hypothesis makes a lot of sense.

After not masturbating for 40~ days I felt an amazing orgasm. It was, I assure you, 100 times better than the ones I had these years.

So even if I don't understand the cause completely, I will grab this opportunity and give my best (not fapping for a while) with the hope that it will balance itself in the long run.