So here's what happened, yesterday morning I was driving to the bus stop(7 minutes from my house) and noticed that my car was blowing cold air even though the heater was on and car was warmed up, turned out I had a coolant leak so I changed out the hose on the side of the road and added coolant, while doing that I let the car run so it would cycle through and as the heater got hot my car ran out of gas, right before it stalled it made some clank sound and now when I first start it up it sounds like I have a fat exhaust leak and keeps that sound till the car warms up then it goes back to being normal, does anyone have a clue what it could be? 98 civic d16y7.

Thank you in advance.

 

Is the engine low on oil?

 

Checked it and it isn't low, checked for exhaust leaks and nothing, checked all fluids and they're good.