What is the ruling on doubting a legal ruling (hukm shar‘i) during prayer, and is it considered to invalidate it? And what is the ruling on women passing or praying in front of me in the prayer area, and does that invalidate the prayer?

The cure for obsessive thoughts (waswas) is to ignore them and pay them no mind. Hesitation in forming the intention (niyyah (definition)) does not invalidate the prayer, according to the more preponderant opinion. Crying, if it is overwhelming, does not invalidate it. The prayer of someone next to you, whether they are ahead of you or between your hands, does not affect the validity of your prayer. Prayer is not invalidated by someone passing by, but one should prevent anyone who intends to pass in front of them so that the reward is not diminished, and one should pray towards a sutrah (an object used as a barrier).