The 8 to 12 week time frame that most people go by is meaningless, no matter what the breeder or seedbank says the finish time is supposed to be,there are way too many variables to use days as an indicator of harvest time,i read where you are checking the trich's so what i just said was to preface my next comment.
Wait it out,not having any sun leaves left alive wont stop the plant from finishing & neither will any ph issues,the ph might slow down the finish time or effect bud growth but the buds will continue to mature,its a process that cant be stopped as long as the plant is growing,its hard to wait especially when you think you've done something wrong causing the lengthened finish time but they will finish, you can be sure of it ,just give them as long as they need,it wont be too much longer.