You've been told in the past that you need to see the character that you're talking to. So, you imagine what he would look like. Hair, eyes, height... Good. So, you find that spot where he would be and you fix your eyes on it. Okay, now; let's forget acting for a minute. Ask a friend a question that you know will lead him into a long story. And, then let him talk. How much does he look at you? Probably very little. Maybe only a surprising 15% of the time! Reference this behavior when you do your monologue. But, just to be sure you're committed to the exercise, only look at your imaginary partner 10% of the time.
Where else do people look when they're talking? The environment around them? Create an environment around you then. When someone tells a story and they're thinking back and remembering images, where do they look? Notice this when your friend is talking and thinking back. Reference this behavior when you do your monologue.
Once you've created an environment, make sure you stay facile with it. Don't allow this imagined world to work against you. Use what's really there in the room too. Remember, when you walk into an audition you may be in that room for the first time. Learn to quickly marry what's really there in the audition studio with your imagined reality. A door is a door. A Window is a window. A table a table. Or, perhaps: a support beam is a tree. A piano is a boulder. A wall is a cliff.
Look at stuff.