I used to be a union rep at one of the UK's universities. 

If you're a member of a union, see your union rep as soon as possible and take advice. 

From my experience as a university union rep, someone in your situation working as a university teacher would be able to get a few days compassionate paid leave, but no more than that - it would cost the university too much to offer more, given that someone else has to be paid to cover the classes you're no longer able to take. It might be possible to arrange a period of unpaid leave, which at least means the money no longer being paid to you can be used for temporary cover.  Perhaps a more practical option is that the timetable might be rearranged to give you some time off each week, or maybe your contract can be reduced on a permanent or temporary basis to give you one or two complete days free each week. 

I don't have any experience with school teaching, but I don't suppose your employers would be able to offer you any more than a typical university.  I'm sorry, because I expect this is most disappointing. 

I used to be a union rep at one of the UK's universities. 

If you're a member of a union, see your union rep as soon as possible and take advice. 

From my experience as a university union rep, someone in your situation working as a university teacher would be able to get a few days compassionate paid leave, but no more than that - it would cost the university too much to offer more, given that someone else has to be paid to cover the classes you're no longer able to take. It might be possible to arrange a period of unpaid leave, which at least means the money no longer being paid to you can be used for temporary cover.  Perhaps a more practical option is that the timetable might be rearranged to give you some time off each week, or maybe your contract can be reduced on a permanent or temporary basis to give you one or two complete days free each week. 

I don't have any experience with school teaching, but I don't suppose your employers would be able to offer you any more than a typical university.  I'm sorry, because I expect this is most disappointing.