First things first, don't blame yourself. There's nothing wrong with mental illness, and you can't change whatever has already happened. You need to look to the future, not the past.

As for university, are you failing the course? Do you actually like the course and uni? If you drop out some unis may be a bit more reluctant to take you, but your doors are far from closed. Most unis are quite understanding about these things as depression, especially in university environments, is unfortunately quite common. I'm sure you had more reasons to drop out from warwick than just not liking the place, but if they were to be a bit iffy about anything it'd be that.