i've offered to fully pay for him if he wishes to go back to college as long as he can keep a 2.0,

Again, this confirms my suspicion that you are an overbearing parent. Offering to pay for college is great, setting conditions is acceptable, but did you ever consider the fact that perhaps he is not as academically gifted as you would like him to be? It could be that his talents lie in other areas, but your tunnel vision that only academic success counts could have led him to feel such an immense pressure that in the end, he just gave up. The way he is right now, not motivated, sitting all day playing video games, having a bad attitude is an accumulation of, what I suspect, is living under the pressure of an overbearing father who thinks of him as a loser. If you are looking for a quick fix that goes from one day to the next, then you will not find it. You need to start to reconnect with your son and get to know him as he is and not as you would like him to be. What are, or more precisely said, were his hopes? What were his dreams? What did he want to do with his life and not what you would have liked him to do with his life?

On the other hand, you cannot continue enabling his behavior of sitting all day, playing video games and not working. So, however you do this, if you kick him out without reconnecting, then your relationship may never recover.