My 2002 Chrysler Town & Country Minivan (3

My 2002 Chrysler Town & Country Minivan (3.3 liter) had the timing belt, water pump, and thermostat replaced about 20, 000 miles ago. Recently, there are several things going on with my cooling system I need guidance on. Looking under the hood, I noticed what appear to be a small hole in the radiator under the big hose on the right. It sprays the hot coolant inside the engine compartment causing smoke. I tried to repair it with a sealant/additive and it didn't work. I must add coolant every 4-5 days. Before when I added it straight to the radiators it overheated almost immediately. I then had to add the coolant to the overflow reservoir which seemed to help at first. Now the van will blow cool/cold air even when then engine is at normal operating temperature. For a couple weeks the cold air would vacillate with warm air with the temperature gauge remaining in the middle. Recently, it not only blows cold air, but the temperature gauge will vacillate between normal and overheating. It will constantly change from almost the highest temperature back to the middle, sometimes staying at 3/4th's. One additional thing that may help to diagnose (it will probably just add to my woes) is that both radiator fans seems to stay on at all times, whether it's overheating or not. I know I need to replace the radiator, just wondering what else you think I should be prepared for based on my symptoms. Thank you very much for your feedback/expertise!