Could this be understood through Hindu traditions, or is there another way to read it?

There isn’t one Hindu occult explanation that can reliably identify a presence from a smell or a particular image. Traditions vary widely, and devotional recitation can be a meaningful way to steady yourself without proving what caused the experience. I’d be cautious about assigning it a specific spirit or omen based on those details alone.

If it would help, you could speak with a trusted, grounded religious teacher who is comfortable saying “we don’t know.” I’d avoid anyone who uses the episode to frighten you or sell a guaranteed remedy.

Check the ordinary source first. A sudden rotten-egg smell can sometimes be the odor added to natural gas. If it happens again and you suspect gas, get everyone outside, don’t operate switches or use flames, and call the gas service or emergency help from a safe place. If there’s no gas connection, drains, spoiled food, or something outside could still be worth checking.

The images and the smell don’t tell us by themselves whether there was an external cause. If the smell returns without an identifiable source, note when it happens and consider discussing it with a clinician.

One episode, even while fully awake, doesn’t settle what happened. A previous evaluation is useful context, but if this recurs, gets more intense, or comes with other new symptoms, it’s reasonable to check back with a medical professional. You can mention both the smell and the visual experience, along with sleep, medication, and anything in the room that might explain the odor.

For now, writing down what you remember and checking the room in daylight may be more useful than trying to force a definite supernatural or medical explanation.