I think I know whats the problem: Your computer got a new internal IP from the router which means that the port forward doesn'r work anymore, you have to change it's IP to the new internal IP of your PC (and I'd recommend you to set a static IP for it)
solution for further problems: try to tell your router that you want a static ip for your pc. If the router doesn't support that, you can try to configure your OS so that it requests a static IP. You can google how to do that.
I wanted to write proper instructions, but as I don't know his OS and router model/firmware version. The post got somewhat useless though...