Based on this new university-level policy, the individual colleges must follow this so everyone should be accommodated and supported by their colleges. I hope you'll be fine soon!
"The University has asked all students who do not live permanently in Cambridge to return home, if they are able to do so. As colleges will likely be operating at a reduced capacity, it is important that they are able to prioritise students who have no other option but to remain in college accommodation. Therefore, if you do not live permanently in Cambridge and are able to return home safely, you should do so.
However, we know this will not be possible for all students, particularly for international students, estranged students and care leavers, postgraduate students, or students with family members who are self-isolating or in high-risk categories. If you live permanently in college accommodation or are unable to return home, you should continue to be accommodated and supported by your college.
International Students - if you are unable to return home due to travel restrictions, financial difficulties, or because it is not safe to do so, your college should continue to provide you with accommodation and support."