Best Answer - Chosen by the Asker
had to = verb +كان يجب ان
i had to pray like that because of the lack of space/ because there was no space
اضررت ان اصلي هكذا بسبب قلة المساحه
Had/have to doesn't have to mean يجب ان/كان يجب ان you may use اضررت which carries the same meaning, but more applicable to be used in situation when you have no choice except doing certain action (like example above).
But for the other school example ,you use كان يجب ان because its something that you actually HAVE to do or obliged to.
As for no choice/no other way = ليس هناك خيار اخر/ طريقه اخرى/مفر
there is no way = ليس هناك طريقه/مفر
there is no choice= ليس هناك خيار
Choice= خيار Way= طريق Escape= مفر
Hope that helped :)
