Sick baby HELP 😢

My son is 5 weeks old and he started off being a little congested a few days ago because our house was dry , so we got a humidifier but it's slowly getting worse . You can hear the congestion in his nose and he has a small dry cough every few hours or so . I'm nervous because he's so little . I'm not sure what to do . I tried suck out his nose and throat but that doesn't help because I can't get anything . Any mom's out there that could give some advice? Maybe ease my my mind? Thank you !