stop leak additives usually cause more harm than good.
the bars "might" have helped with you was just leaking a little bit here and there, once it got to a qt a week, no good... now a qt a day? that is a serious leak, you should be able to see where it is coming from NOW for sure.
I am not a fan of leak additives, I think you should look at changing your timing belt and all gaskets and tension pulley.. Then that only leaves the rear main seal and well, that one is a PITB too, but mostly just time consuming, as dropping the trans and oil pan..