u/AggravatingProof9

I have a 50 year old house and 20 year old windows. Upstairs is much colder than downstairs in the winter and much warmer than downstairs in the
Summer (5-10 degrees each way). I have blown in insulation and im not even sure my exterior walls have insulation since they’re ice cold in the winter and a bit on the warmer side in the summer. I know insulation is a big problem but i want to know if spray foam will fix it.

I have a large attic fan
On windy days i can hear the wind through a couple of Windows in my house

Would insulation be a waster of money so long as i can hear wind through some lf the windows in my house? I never feel the draft but just can hear the wind through a couple of the 2nd floor windows.