My main heating pipe is leaking a lot of steam and it fills up the whole basement. Also the furnace/boiler runs out of water quickly. Will my house catch fire?(I am constantly refilling) It seems like it takes forever to warm my upstairs. What are my next steps?

Probably not catch fire due to the water load but sure costing you money.? Next step? Call a plumber or fix the leak yourself. You should be able to at least apply a temporary patch with a clamp on repair sleeve. It will take forever to heat up if you keep adding cold water and maintain low pressure.