Small coolant spray in engine bay from radiator area has turned from topping off to no hot air blowing until high speeds?

About a year ago I did a coolant change and ended up having to jack the car up at an angle and hold a certain RPM to get the air bubbles out and eventually got hot air to come out.

Car drove fine for about a year with no major issues other than what seemed to be a very small depletion of the coolant from the reservoir which I topped off maybe once a month.

Fast forward to today and the coolant has to be topped off once every two weeks but now out of nowhere there is coolant spraying from somewhere along the top of the radiator, I can't locate exactly where.

Topping off the coolant reservoir seemed to be enough but now upon start up I only get cold air until I reach a certain speed / rpm range at which point hot air starts to flow. The second I come to a stop only cold air comes out.

Just last night however the temperature gauge started to rise to a worrying level as I stopped to get gas, I'm thinking that there's still air in the system and it somehow clears up at higher speeds which lets the hot air come out.

I don't want to cause irreversible damage and want to get some opinions on whether it's just too risk to drive the car at all until I get that issue fixed?