2000 Chevy Impala Blowing cold. But not hard

My impala has been a really good car. With only small issues. But recently the AC is having issues. It's blowing cold. Out all 3 areas. Bottom. Defrost and front. But only on setting #5. It's not blowing hard enough to make a difference in this 100 degree weather. I have 3 kids. So I gotta get this fixed quick. Without spending hundreds to figure out what it is. Can you help PLEASE!

Thank you!