“Is it damaging to wear earplugs every night?”

If you are wearing earplugs to keep external sounds quiet it should not be a problem. If you are using them to silence tinnitus or ringing in ears, it will exacerbate it. For the ringing its better to use a noise machine like a dohm available on Amazon. The other thing to keep in mind is moisture in your ear. If you have a tendency to get itchy ears, external otitis, drainage, or ear infections you should avoid plugging up your ear so air can circulate. If noises or sounds in general are frequently bothersome its good to see an ENT or audiologist to have your ears/hearing evaluated.