Thanks for your question. I will try to help.
As a student you are required to have comprehensive sickness insurance. If you have not had this until 2 days ago, then the time you have spent in the UK up until 2 days ago will not count towards permanent residence (which is what you get after 5 years).
So, assuming there are no changes as a result of Brexit, you will qualify for PR 5 years from two days ago provided that you continue to exercise your treaty rights in the UK.
It is unlikely that final Brexit arrangements will deny EEA nationals already in the UK the right to stay in the UK until they reach 5 years and qualify for PR.
In the very unlikely event that this right is denied to eea nationals as a result of the final Brexit agreement with the EU, you would probably be able to secure you leave to remain on the basis of being an unmarried partner if you have lived together for 2 years at the point at which you apply. The government webpage on this is here:
In the event that the Brexit arrangements deny the right for eea nationals to stay in the UK for a sufficient time to allow them to apply for PR AND at this point you have not lived together for 2 years then you would have to carry out a civil partnership with your partner and then apply on this basis because you must be cohabiting with your unmarried partner for 2 years to legally be regarded as “unmarried partners” for the purpose of obtaining a visa.
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