This season

The pollen season has come;((I have an allergy to ceder pollen.
I hate this season because my nose won't stop running and I can't stop sneezing.
I feel bad, and I always have to have a tissue (with me).   ("with me" is optional, but it might make it sound more natural).
Some of my friends also have an allergy to ceder pollen.
Now it is only that treat symptoms as they appear...    

"Now I can only treat the symptoms as they appear..."   This sounds more natural.
I wish that a new medicine for pollen allergies would be developed in the very near future.

All in all very well written. Just a few changes here and there. Good luck with your English studies and with your allergies.