Do your top choices know you were prevented from attending due to your health? Were you already enrolled when you had to withdraw?
Will your health be getting better, and do you have any timeframe? Or is it the sort of horrible disease that never gets better?
Do you think it’ll be possible for you to study abroad later on?
Since you’re under 26, aren’t your health expenses covered, or can your parents improve their plan’s coverage with a lower deductible?
Is the matter keeping you from the flagship your health or costs?
You wouldn’t be going for a Master’s degree. For History/Archeology, you’d be going for a PHD. And PHD admissions depends upon research ability. So yes research is essential. (Also: any PHD worth doing is funded meaning you don’t pay tuition and generally receive a stipend and, in history, should only be done at top programs.)
Check out whether the small school has an honors college/program and what it entails.
And it sounds like it wouldn’t be possible at the smaller school nearby, nor with the UK online school.
So, we need to think creatively about this.