"Addicted" to sinus rinse after rhinoplasty?

I had a rhinoplasty about 3-4 weeks ago, and when my doctor removed the cast (a week later) he recommended i use a sinus rinse for about 10 days in the morning and before bed. Problem is, now i can't stop because whenever i do, i have to breathe through my mouth because my nose gets really congested and blowing it isn't enough... What should i do? Is this normal? Is it okay to use sinus rinse twice a day everyday? Thanks!