21 year old male. My libido appears to have decreased significantly. Is this normal?

Sorry if this question is too graphic. I have been single for about a year now and I appear to have lost almost all interest in sex. I used to feel extremely horny at least one or two times a day for…well for about as long as I can remember. But for the past two weeks I have had no interest in sex at all. I wanted to chalk it up to stress, but frankly I am not that stressed. I am graduating college very soon, so I am a bit anxious to make that transition, but it feels like a copout to blame it entirely on that because it is not affecting me too much (I have experienced far bigger transitions, FWIW).

I get a pretty normal amount of exercise – I don’t work out at the gym or run, but I am far from sedentary. My eating habits have been roughly the same as always.

So what is going on? Is this normal? Has this happened to anyone? Did they get over it? Was it a symptom of something larger?

Please help me. I miss craving sex. I want to know that I am capable of enjoying sex again.