Definitely sleep apnea. I recorded myself before and heard another 2 people with sleep apnea while sleeping in the same room. All of us have the same pattern: Start of the sleep with very loud snores, then suddenly go very quiet. This is typical of apnea because the breathing has paused so no more snores. Then, your body will gasp for air after some time of no breathing, then quiet again.
If I'm not wrong, the loud snores at the start is the tongue beginning to collapse so the airway starts to get blocked and this causes loud snoring. Once the tongue fully collapses, air intake paused so no more snores. Until your body wakes up momentarily to gasp for air, then you breathe in. But this time, your tongue collapses faster so usually don't hear much snoring, maybe a few snorts then quietness.