Coolant leak repair?

Yesterday I found that my coolant was gone, filled it up but car started overheating right away and shaking when I pressed the gas. Got it towed to my house and the next morning filled up the coolant again, took it for a five minute drive, there was little bit of smoke under the hood but temperature gauge was still in the middle of hot and cold, in the five minutes I drove it. It had also swallowed up about a quarter of the coolant, looked under the car and there was no leak under the coolant tank, but spewing on the passenger side (left side) of the under the hood. I wasn’t able to get a good visual, whatever is causing the leak was below the engine or to low down for me to get a good look. Left the car running idle, very little to no smoke in the ten minutes it was running on my driveway, it actually only really smoked up after I turned the car off. But coolant spewed out like crazy. Heater didn’t really warm up either. Checked the color of my oil to make sure coolant hadn’t mixed in and it was fine. My oil is still dark brown and regular, any ideas as to what part of my cooling system could be causing this? I’m thinking maybe a hose? The first night it overheated I suspected it was a stuck closed thermostat because coolant wouldn’t leak but the car overheated, the situation completely changed the next morning, suddenly a leak! Also noted that when the car was off I didn’t see any coolant spewing out. I know Subaru’s are infamous for head gasket failures, but it really could be any part of the system, please help!