Babies with allergies?

Kj • Mama of 4 beautiful girls 💕💕💕💕

My daughter is 4 1/2 months old and appears to have allergies. The last few days she’s had a runny nose that ran clear and she’s been rubbing her eyes. But today she’s got this god awful cough like she’s choking on mucus and when she spit up earlier it was pretty mucusy. She’s having a tough tone nursing now because she can’t lay flat for too long. We’ve been suctioning her nose and giving age appropriate medicine for cough and mucus relief. Does anybody know what else I can do? I hate seeing her like this.