Help! My lil one has a block nose that I couldn't clear.

Please kindly share more information about this. My baby girl is 3 months and 11 days and she has a clear situation of blocked nose. I've tried applying saline solution/use a nasal aspirator and went to the PD which gave a medication to add into her milk which honestly I don't see the effect of her nose clearing up at all. Its getting very worrying when she squirms a lot and walk up bursting into tears in the night when she is trying to sleep. Any ode