Sneezing in blocks. Tell me what to do.

Normally a sneeze or two occurs to me when something irritates my nose passage. But this is not very often. And it's very common. Lately, from a week, I have been sneezing a lot. In a block of 10-12 sneezes in the morning after waking up. During the day i hardly sneeze. But in the evening and night it again starts. Sometimes even mid sleep. Generally when I start sneezing like that i take a tablet of lezyncet at night and that is the end of it. But this time I've eaten 3 tablets(one every 2nd night) but still it somehow seems to persist. Any strong odour like tadka or anti pain sprays or even coconut oil sets off these sneezes in the evening. At morning and night it's generally automatically. When the sneezes happen, the nose gets runny, my eyes get watery, and specifically the left nostril jams up. After the block of sneezes, my head hums (basically a mild headache starts to form). I have no other symptoms. No rashes or body ache. Kindly tell me what to do..