OP,
If the US is genuinely too far I completely understand. But if you’re understandably put off by the stated fees at the top universities and elite colleges, please know that some of them have excellent financial aid with parity for international students. For example, Harvard practises international needs blind admissions and a family with an income less than US $100,000 neither writes a check nor takes a loan. Then there is a sliding scale.
The Fulbright Commission, which promotes bilateral educational opportunities between the US and the UK, has good information on its web site. There are other sources as well.
(It is named after the late, distinguished Senator William Fulbright.)
Also the elite four year colleges are worth consideration. The most elite are about as competitive as the Ivy League. These focus on teaching rather than research. The academics are superbly qualified; in STEM, after postdoctoral experience they have chosen to foreground teaching rather than research. Small classes, lots of interaction with staff, better chances for independent study and UG research, etc. Preparation for PG study and employment is the equal of anywhere - highly respected (I found this to be true). The Fulbright site should discuss them. We have a MumsNetter who had one DC at Oxbridge, one at an Ivy and one at college. The college student had the best experience.
In America not only do you have general studies during the first two years, it is fairly common to ‘double major’ in maths and CS.
Not trying to sell you on this, but for a general scholar it seems worth a thought.