I've begun to dream in Portuguese every once a while. I don't remember much when I pick up, but I can hear Portuguese words immediately after I wake up. This is encouraging.

Read wikipedia articles about things you're interested in, in Portuguese. When you have an impulse to do something on the internet, see if it can be done in Portuguese.

It's easy to keep going when you are getting constant, visible feedback, but the real endurance comes when that feedback/visible progress goes "underground" for a while. I'm getting better at that.