Sick baby

I got sick about a week ago , I’m just now getting over it slowly and baby is showing the first couple of signs I had in the beginning runny/congested nose. She has been irritable and fighting sleep I’m sure because this is the first time she has been sick and she is wondering why the heck she can’t breathe from one of her nostrils anymore which is so uncomfortable. Anyways what I got on here to ask is , what do you do when baby is congested and on the verge of getting sick , I’m hoping to try and prevent it from getting any worse because I was absolutely miserable, and I don’t want her to feel like that . TIA