Why not try doing a 1 or 2 years masters in the UK and then apply for PhD? You can definitely try getting some good research and recommendation letters while strengthening your GPA (but it's hard in UK schools though). I also did my undergrad in the US but I got rejected everywhere by top20 US...
Just got rejected by nearly all of my grad schools (one hasn't reply but the chance is pretty small).
The funding is super harsh this year in my field and even worse for a student from China. Is there any way for an international student to take a gap year for physics research in the U.S? ( My...