In winter, the dry temperate weather can irritate and inflame the delicate lining of the nose which can then break out into sores and blisters. If you suffer from allergy problems with your nose, that makes it even more sensitive to changes in temperature and humidity. The simple solution is usually to apply some antiseptic ointment as a barrier to protect the nasal lining.
Of course, we have to consider that underlying deficiencies in nutrition may lead to a breakout of these sores, such as lack of vitamin C and zinc. I do hope you are managing to eat a well balanced diet filled with plenty of fresh fruit and vegetables.
It is worth having an ENT specialist examining your nose carefully to see if there is a deeper source of those troublesome sores inside your nose.
Hope you feel better soon.