Hi, Sonja. If you have left the bleeder valve open all night with nothing--steam or water--coming out, there is a simple answer. There is no steam or water coming through the pipe to your radiator. Is there a valve at the bottom of your radiator on one end? Is the valve open? Turn it counterclockwise to open. If you open the valve and nothing comes out the bleeder valve, then no steam or hot water is getting to your radiator. Resolving this will take more than you can do.
If you open the valve and steam or water comes out, be prepared. There is probably a better than average chance that the radiator leaks and that is the reason that it was closed off in the first place. If you get real lucky and it doesn't leak or the quantity of leakage is small enough to be easily caught in a pan and the pan emptied every so often, you can use the valve to regulate the amount of hot water or steam coming to the radiator and thus, how hot it gets.