How warm does your temperature gauge get up to? Does it get to the Normal area??
What temperature are your heater hoses going to & coming from the heater core?
Feel the heater hoses, they should be very hot. If one hose is hot & the other one is cold, then you have a clogged heater core.
If both hoses are hot, then you more than likely have a temperature blend door that is broken or a temperature blend door actuator or control knob concern.
I have given you things that need to be checked & a direction to go, I cannot fix the vehicle myself over the computer.
I need assistance from you either as the mechanic or owner that is going to fix it hisself. I am opting out because you are very impatient & unwilling to take advice.