My lades in need of a emergency

These plants were given to me in flower stage im a first time grower did research but cal mag just aint working all my leafs are falling off what do i do i think its developing seeds the strain is Oil Spill

I'd consider this crop a loss and maybe any subsequent crops for the next year. Read around on the forums, growing isn't hard but there are a lot of moving parts and it takes some time to iron out all the kinks.