I don't know why anyone would suggest flushing the bejeezus out of it, it won't achieve anything, just continue with what you are doing and look forward to some home grown delight soon enough.
However, autos aren't known for being overly productive, far better to stick with real plants, - photoperiod ones!
Upgrading your light would help (150watt isn't going to set any records) with both plant and flower size, as will buying quality genetics from an established quality breeder.
I can recommend Sweet Seeds wholeheartedly.
Defoliating your plant didn't help either, your plant needs every leaf it has to make the energy she needs to grow her biggest and best flowers.
Just remember -
Maximum amount of healthy green leaves = maximum energy production = maximum growth.
Cheers, Organoman.